Chris's adherence to the ascetic principles set forth by the likes of Henry Thoreau and Leo Tolstoy set him on a path of self-righteous rejection of the rampant materialism with which he was raised. Chris grew up in an affluent suburb, raised by parents who enjoyed the lucrative gains of their hard work. Chris's household was abusive, though, and his father had fathered a child with his first wife after marrying Chris's mother. Chris saw such violence and hypocrisy as further evidence of wealth's corruption.

However, it is important to note that Chris's rebellions against his privileged upbringing were very much enabled by that very privilege. Being white, male, straight, able-bodied, wealthy, and college-educated allowed Chris to pursue his wanderlust and voluntary poverty with a golden ticket out of that lifestyle whenever he wanted it. The book suggests that Chris's Alaska adventure was to be his last before he began living more conventionally. Thus, it seems that his rebellion was a phase that is natural to many post-adolescents, but exacerbated by his particular family situation and made easier by the very privilege he was deriding.

Chris rejected his parents materialistic lifestyle because he thought his father used money to try to control Chris. He didn't want to be controlled, so he rejected what was being used as leverage. He even went so far as to burn his cash when he set out on the road. Chris had learned firsthand that money doesn't buy happiness: there was a good deal of tension in his affluent household as he was growing up, as well as conflict between he and his father as he became a young adult.

Beyond that, Chris had immersed himself during his college years in writers who rejected materialism to embrace a simpler way of life closer to nature, such as Thoreau, Tolstoy, and Jack London. He carried their books with him on his travels and took seriously their wisdom about how to live a full and vital life.

Chris was an intense, stubborn and determined young man, much like his father.  When he and his sister were young, their parents worked long hours at an aerospace business that Walt had started, which left little time to spend with the children, but brought a lot of money to the household, making Chris a child of some privilege.  The real difficulty arose when Chris discovered the truth behind his father's divorce from his first marriage.  Walt began a relationship with Billie (Chris' mother) and fathered Chris, while still being romantically involved with his first wife.  Walt lived a double life, even fathering another child with his first wife despite having a life with Billie and his new family.  When Chris found all of this out he considered his father to be a hypocrit, and never forgave him. (Krakauer, Chapter 12)

Chris McCandless was very angry toward his parents, but why isn't really clear. More of his anger is directed toward his father, and we know he condemns his father for the end of his first marriage, holding his father to an extremely high standard. Perhaps Chris and his father were too much alike or were too different to be able to get along. Many times, fathers will hold their sons to a high standard that the son doesn't feel he can ever achieve or live up to. Chris also felt his parents were tyrants, and he was resentful and bitter toward them. He was at an age where he wanted to prove himself, and his adventure into the wilderness seems to be a journey to find some truth about mankind. There's no doubt Chris was stubborn and determined and wanted to do things his way, which of course led to his death in the wild.

In Into the Wild, why did Chris McCandless hate his parents?

It's not so much that Chris hates his parents as that he hates the lifestyle they lead and the values they embody. Of course, he harbors a certain degree of resentment towards them for their keeping family secrets from him—it turns out that Chris was born out of wedlock, for instance—but that doesn't provide his main motivation for dropping out of society and heading north to Alaska.

Even if Chris's parents had clued him in on everything that went on in their lives, he still would've taken off. This is because they lead a lifestyle that he regards as phony and inauthentic. Their superficial attachment to the fruits of capitalism is something he finds positively soul-destroying. Chris's parents have come to represent the values of consumerist capitalism, and due to his sensitive, individualist nature, their son wants no part of this.

In heading out into the wild, Chris is effectively seeking to make good what he sees as the deficiencies of his upbringing. By reconnecting with nature, he's teaching himself all those things that, for one reason or another, his parents didn't teach him. He may not hate his parents, but he has to reject them and everything they stand for if he's to set his feet firmly on a different path in life.

In Into the Wild, why did Chris McCandless hate his parents?

In Into The Wild, Alexander (formally known as Chris) rebelled against the authority of his parents, particularly his father, and the capitalist lifestyle they led. Alex sought to make his life free from the confines of parental authority and parental expectations. He certainly resented his parents for lying to him about the circumstances of his birth and his parents' relationship. As he began forming an anti-capitalist/anti-materialist view, he became more distant from his parents, who represented both capitalism and authoritarianism.

Anti-authoritarians often interpret the structure and function of the nuclear family as rooted in authoritarian ideologies that particularly harm the development of children. Through authoritarian nuclear family structures, children are often taught to merely obey their parent(s) rather than develop critical thinking skills or to question authority. Alex understood how, in our dominant society in particular, parents are often sources of authoritarianism through raising children to accept "because I said so" as a valid response to challenging authority. Alex may not have hated his parents as much as he hated what his parents represented and the systems in place that create and encourage authoritarian parenting structures. Alex, in his journey to Alaska, sought freedom from this authoritarianism and materialist way of navigating the world.

In Into the Wild, why did Chris McCandless hate his parents?

Chris had issues with his parents, in particular, his father. He was shocked when he discovered that his father had another family he had never been told about, and that, in fact, his father had not been married to his mother when he was born. This information made him feel that his whole childhood had been based on a lie. 

But beyond that, Chris had deep issues with his parents' materialism. They had worked hard to build a business, but Chris felt that his father tried to use money to control him. Being strong-willed like his father, he chafed under that control, and he decided that as soon as he had graduated from college, he would break free from those bonds.

In college, Chris's reading of countercultural authors such as Thoreau and Tolstoy reinforced his ideas about rejecting materialism. Like many young people, he was trying to establish his own identity, and this, along with his other issues with his parents, led him to reject both them and their values. 

In Into the Wild, why did Chris McCandless hate his parents?

Chris didn't really hate his parents; in fact, going by his letters (all sent before he vanished from their lives) he still loved and respected them. However, he felt trapped by their insistence on living within societal boundaries; he felt that they were pawns of society instead of individuals, and so their influence restricted him from pursuing his own goals.

Both father and son were stubborn and high-strung. Given Walt's need to exert control and Chris's extravagantly independent nature, polarization was inevitable... He brooded at length over what he perceived to be his father's moral shortcomings, the hypocrisy of his parents' lifestyle, the tyranny of their conditional love.
(Krakauer, Into the Wild, Amazon.com)

The similarity between Chris's personality and that of his father was one of the problems; similar people tend to grate on each other, especially when one is in direct authority. Chris felt that his parents, while meaning well, didn't understand the ideals that he had learned from Tolstoy or Thoreau, and that they were addicted to the pursuit of material wealth just like everyone else in society. Instead of speaking with them and finding common ground, he rebelled in passive-aggressive ways. When he finally started his journey, he resolved to never contact them; sadly, he held to this resolution until it was too late.

In Into the Wild, why does Chris McCandless isolate himself from his family?

What causes Chris more than anything else to isolate himself from his family is both the materialism that they live their lives buy and also the fact that his father had a previous wife and had carried out relationships with her and with his new wife, Chris's mother, at the same time, fathering a son by his previous wife at the same time he fathered Chris. For Chris, who put such value on honesty and integrity, his father's double and duplicitous life meant that he had lost respect for him, as the following quote makes clear:

Chris kept careful score. And over time he worked himself into a choler of self-righteous indignation that was impossible to keep bottled up.

Chris therefore chose to distance himself from his parents because of the way that he sees them as being materialistic, but also because of his father's past misdemeanours in his previous marriage whilst also pursuing a relationship with Chris's mother. Chris later said to his sister that this revelation made his "entire childhood seem like a fiction," and it can be understood how his parents came to embody everything that Chris, in his desire for simiplicity, purity and truth, stood against.

From Into the Wild, why did Chris McCandless reject the lifestyle of his parents?

Chris is described as being a self-taught student of Tolstoy, Thoreau, and Transcendentalism; his ideals focused on self-growth and harmony with nature, not on materialism. Chris grew up in an upper-middle-class family, and so was attuned to the great privileges he had received in life, especially compared to others. Chris decided that his life should be spent in work and self-reflection, and so abandoned his family and set out on the road.

At long last he was unencumbered, emancipated from the stifling world of his parents and peers, a world of abstraction and security and material excess, aworld in which he felt grievously cut off from the raw throb of existence.
(Krakaur, Into the Wild, amazon.com)

Chris had a basic ideal: that humanity was too focused and obsessed with material goods and money, and that they had lost the most important focus of all, that of harmony with nature and with fellow man. Chris found his parents to be part of he culture that he rejected; they wanted him to go to school, find a career, and follow their own paths, but he wanted to find his own path without coercion. In the end, he overcompensated for what he felt was an overprivileged life, and moved to the opposite extreme, without a home or family.