I don't have a lot of time to spare right now, so I'll get right to the point:
There is a huge difference between moral capitalism (what product/service can I provide to make someone's life better/more convenient) and amoral capitalism (how much money can I make and damn anyone else).
Countries do not fall because of their economic policy (there are excellent arguments for each system). They fall because of a lack of principles and morality. What we are seeing in America now (and for several decades) is a huge swing towards amoral capitalism.
This is why Bernie Sanders, for example, is resonating so well for a certain segment of the population. His argument isn't a scholarly exercise. He's playing the "good vs evil" angle. He's turning it into a moral argument, saying (erroneously) that capitalism is inherently evil and Big Government will fix it all.
You can have amoral crony capitalism. You can have amoral crony socialism. The constant, and the problem, is the "amoral" and "crony" parts.