The problem with communism is that it's beautifull in theory, then get's screwed over in practice.
The idea starts with the government pretty much governing all. A central body capable to oversee and direct for the good of it's people. In practice, this made the whole government sluggish, immobile. When winter hit Siberia, it would take the Soviet Union well into summer before the whole process of sending extra winterclothing to Siberia complete.
Also, the economic model does not work with actual human beings. You'd get people standing at a shop to open a door just so everyone had work. Or people doing other mundane, unnecessary tasks merely to reach a 100% employment rate.
Link this to the fact that all pay should be equal and there was hardly any incentive for any skilled people to optimize potential. Why would I go through eight years of medschool to become a doctor if I make the same as a guy opening doors all day?
A communist model can only sustain itself in an ideal world.
The Doctor will see you now
Promoting Lesbianism --> 
