First, let me construct a definition of capitalism:
Capitalism is the system of free trade where all economic actors involved in the trade of goods or services are able to retain the gains from those trades.
From that definition, I presume many people would say, "What's wrong with that?"--people ought to be able to keep the money they earn. After all, the people gained by their own efforts. But people make the system of capitalism into much more than a mere system of free trade. They make it a constant and ever-present incentive to reward man's depravity.
Last week a young woman decided to auction her virginity on a radio show. When asked why she would sell her virginity, she remarked, "We live in a capitalist society. Why shouldn't I be allowed to capitalize on my virginity? . . . I'm using what I have to better myself." Did the ability to sell her virginity corrode her morals or were her morals sufficiently corroded by other influences to the point she would consider such an act? The problem of immoral behavior is not rooted in capitalism but in the depravity of human preferences. There are less outlandish examples as well, like the father who trades time spent with his children for long hours at the office to buy new toys. Did capitalism corrode his moral obligation to be the father of his children? Perhaps capitalism provided an option that, because of his weakness, he did not turn away from.
That we can be rewarded for distortions that we are willing to make to our own morality does not mean that capitalism corrodes our morals. Maybe capitalism is an ever-present incentive for some people to engage in questionable behavior. But temptation and compromise of character lurk around every corner in non-capitalist institutions as well (relationships and politics). There is a common indictment that markets are evil and create evil. But evil does not need the free market--it just uses it as a vessel sometimes.