The anti-capitalist argument centers around "greed," "exploitation," and "inequality." Long term "greed" and "exploitation" are untenable. Entrepreneurial arbitrage will punish greed and exploitation in the form of loss of competitiveness or loss of goodwill. In the short term, the scarcity of resources of capital can manifest itself in a large amounts of profits. It is possible for individual actors to act with great selfishness during periods of great scarcity and amass large amounts of wealth.
This is individual failure of morality. It is not a moral failing of the system. But greed and selfishness is a far more universal than anyone would like to admit. While they might like to condemn the greed and selfishness of others who have made their wealth by greed and selfishness on a grand scale, it is far more difficult to come to terms with the small amounts of wealth that oneself has gained by greed and selfishness on a small scale. The condemning of greed and selfishness starts by looking in the mirror.
The final arguments concerns "equality" in the form of discrimination. But while there is a lot of inequality in the world, none of it is attributable to the free market. It is the failure of society that racism, illiteracy, poverty, and many other vices persist to this day. The spearhead for the "equality" argument is not born out of a benign desire to give everyone what they deserve but out of a malicious manifestation of envy to tear down the successful.
The effect that we see in the world is that white-collar workers and intellectuals often overvalue their own contributions to society and undervalue the contributions of society of the entrepreneurial class. They look upon the New Rich with supreme skepticism that the wealth was accumulated legitimately. Perhaps, the New Rich practiced some form of Voodoo Wealth Distribution and stole all of that wealth from the rest of society instead.
White-collar workers look upon their bosses and belittle their contributions. They only see the paper pushing and the mindless administrative jobs that they can handle. They don't see the creativity, the awareness, or the perseverance that the entrepreneurial class must deploy to succeed against the competition. Intellectuals will often have a high assessment of their own intelligence and creativity, and look upon the entrepreneurial class with disdain. Yet the free market doesn't confirm their disdain since the free market rewards people that actually satisfy people's needs - not ivory tower types that dream up unproven ideas.
While supporters of free markets and capitalism can debate amicably with anti-capitalists, but when the debate falls to moral outrage, it is imperative that we attack all manifestations of envy in the anti-capitalists and show it for the evil that it is. The conversation may turn sour, but supporters of capitalism are not moral voids. We must defend the moral high ground.