To be sure, capitalism is the most efficient mechanism for developing prosperity. Yet like any delivery system, is subject to the vices and virtues of those who use it. Inasmuch as economic power is decentralized in capitalist nations, so too is political power. Conversely, socialism is said to appeal to people's altruistic impulses. It is, again, prosperous to imagine that altruism has replaced self-interest as the main driving force in socialist societies.
Human nature is universally the same.
The above criticism confuses greed with legitimate self-interest. Such interest is not synonymous with greed. I am rewarded most when I succeed in meeting the needs of my neighbor by efficiently providing the goods and services desired. Sharing is a cheerful response to grace. Coercive redistribution of wealth violates the commandment that rich and poor be treated alike.