many many reasons and did* but the main one is it allows the people to be wealthy and free, which is the exact opposite of the communist idea which is for everyone to be equal. being equal doesnt sound to bad right? well it was everyone was poor and the politicians were rich from the insane amount of taxes. The USSR was among the poorest countries for a long time because people didnt work because why work when you still get the same amount of money if you had worked. Where as capitalism is the idea that if you work you will succeed in life and move up in the economic scale, but if you didnt work you would be poor and most likely stay poor