General Discussion

Perhaps Communism devolves into totalitarianism over time, that I don't know. We have never seen a truly democratic communist system. Communism is an economic system where the state (which could be a democratic state or a totalitarian state) manages the means of production and distribution of goods and services. It is based on the desire to remove class structure, which may or may not be realistically possible.

This is only my under informed opinion, but I don't think any one system of economic organization can be sustained once populations grow past a certain level. Not capitalism, not mercantilism, not communism, or socialism. There is usually a combination that is needed.

So back to the question of hating communists. Yes, they were painted as subversive and evil because they threatened the capitalists and when the USSR started their fiasco and extreme authoritarian and totalitarian regime, along with Mao, it gave a really bad face to communism as a system. Whereas Nazism is in and of itself a morally and ethically repugnant system.