"Good" and "bad" are human inventions. They are common values upon which we all agree to live together. "Good" and "bad" are defined by laws. If you have a different understanding of them, you'll be an outlaw. This isn't fair from an objective standpoint, but certainly fair to the citizens.
Markets are fine for luxury goods like iPads and expensive shoes, but crucial items such as medicine, and important public services such as the Police, Army and Fire Service, should not be subject to the often short-sighted profit-based motives and instabilities inherent in Capitalism.
In theory Capitalism is not particularly problematic. However it's practical implementation has resulted in a strengthened ruling class that drift between business and government interests. Corporations write laws to benefit themselves. This is incompatible with Democracy and hurts the lower classes
It's a socioeconomic system that places ultimate authority in wealth. Either the wealthy have control of government, or they seek to eliminate it. Removing the authority of government doesn't rid us of authority, it merely transfers all authority to the super wealthy. The end result is feudalism.
Capitalism is just a system (and as such, is neutral). You can think of other systems but they will all be flawed in a way or another. The biggest flaw is the humanity itself. If you think the system is rigged, try to fix it first (that's the purpose of politics) rather than throw it right away
at the present, we are keen to just talk about the things which are considered as a problem instead of trying to fix them. If something is seen as a threat or problem and the only thing we do about it is just talking, then it eventually means that IT is OK. So capitalism is literally OK.
Capitalism is OK for now, but it relies heavily on unlimited economic growth, which will sooner or later be impossible in a world with finite resources.