Capitalism is against the things that we say we believe in - democracy, freedom of choice, fairness. It's not about any of those things now. It's about protecting the wealthy and legalizing greed.
Greed has been with human beings forever. We have a number of things in our species that you would call 'the dark side,' and greed is one of them. If you don't put certain structures in place or restrictions on those parts of our being that come from that dark place, then it gets out of control.