Capitalism, socialism and communism are purely economic systems. Whether they are good or bad for a country is determined by whether or not citizens have a say in their government.
Under Stalin, people had no say and millions died, so people think communism is bad.
Under our predatory capitalistic system, the oppression is more subtle and insidious. The powerful have the ability to shape our view of reality and influence our opinions to the point that we support candidates, policies and laws that are clearly not in our best interests.