I don't think your statement would apply to the world's population. I think there are cultural factors that should be considered. Our culture stresses competition and the accumulation of tangible goods. That just seems to be the American way. Within our culture, however, there are subgroups of people who do value love and family over money and goods. I think priorities and our value system is something that we are raised to accept and desire.
The question makes some broad generalizations about human nature that might have to be fully questioned. I would say that there is probably less of lives "being aimed at making money" now than there was at other periods of history. If you look at the structure of individuals and their relationship to work in the a decade such as the 1980s, you would find more individuals who are geared towards materialism than in the modern setting. Additionally, the question makes the assumption that generating wealth and success is mutually exclusive with the concept of loving. This helps to make a false paradigm: Those who win are heartless and almost dehumanized machines, and those who lose are beings that live with their heart. I am not certain that each classification is entirely accurate.
Making money is what puts roofs over our heads and food in our mouths. I do not think that people generally believe that money and winning is more important than loving. In reality people have to go to work every day and earn money to pay the bills so making money is a necessity, but not necessarily more important.
In addition, we live in a very competitive world. For example, people must compete for jobs in order to support their families. It is in our nature to be competitive but it is also in our nature to be loving so I believe we are both.
Of course, this is simply an opinion question. And I am actually not sure that most of us do this. I think that most of us live our lives trying most of all to do what is best for our families, however we see that.
But taking this statement as true, I would say that it is caused by the values of our society. We are a capitalist society and capitalism encourages people to compete. We also have this view of ourselves as self-reliant individuals, the descendents of the pioneers who "won" the West. Because of this, our society really emphasizes competing and making money.
The simplest answer to this is that people do what they believe will give them happiness. So when, people believe that making money will give them greater happiness than loving then they give greater importance to making money than to loving. Of course weather a person is right in believing that either money or love is more important, is quite another matter.
Second, reason is that whatever is more concrete has greater motivating power. Love is something we all talk about, but reality is that even great scholars find it difficult to define and agree on "what is love". Thus love is something quite woolly or hazy as compared to money. therefore money has greater power to motivate because it is something very concrete and clear.
Finally, money is helpful even in loving. It is very difficult to be compassionate and loving when you are dyeing of hunger. If a person has to work over time to just make two ends meet it is difficult to find time for loving, or to buy gifts for your wife. Bur if you are rolling in money, the situation is quite different. Even great souls like Mother Teressa, who were full of love and compassion, did not neglect the job of obtaining funds for her charitable work.