This is, of course, a matter of opinion. I will give you arguments both ways and let you decide which argument you like better.
On the one hand, you can argue that the American complaints were certainly justified. The British imposed taxes on the colonists without allowing them to have any representation in Parliament. This is definitely unjust because people should be able to have a say in the laws that apply to them. Moreover, the British government imposed some taxes, like the Stamp Tax, that were not external taxes. The British government had even less right to impose taxes on things that happened completely within the colonies, as opposed to trade between the colonies and other places. For these reasons, the colonists were well justified in complaining about taxes.
On the other hand, if we think about the taxation of the colonists in comparison to the taxation of the people actually living in England, it is much harder to justify the colonists’ complaints. First of all, there were many people in England itself who were being taxed without any real representation. England was not the parliamentary democracy, with full voting rights, that it is today. The average American, then, was not really being treated any worse than the average Briton. What is more, the average American was actually taxed at a lower rate than the average Briton. Taxes on the colonies were actually lower than taxes in the mother country. Finally, the Americans complained when internal taxes (like the Stamp Tax) were levied, but they also complained (and destroyed property) when the Townshend Acts imposed external taxes on things like tea. The Americans were actually better-off than most Britons and they did not hold to their supposed principles on which taxes they would accept. They were not oppressed enough to rebel.
Which of these arguments makes more sense to you?