You can't use Capitalism to gain an upper hand on your fellow man. Thats why it's been so poorly described. Capitalism is the separation of economy and state. It requires a society of emotionally mature adults. The real evil the Left sees in it is that is thwarts the Principle-Agent Dilemma that allows statist forms of government to develop.
Nobody can rule the world with Capitalism, thats why the Left hates it.