OK, here's a non-utilitarian answer: People really like owning and controlling their own stuff. (I suppose you could make that a utilitarian statement, by say

OK, here's a non-utilitarian answer: People really like owning and controlling their own stuff. (I suppose you could make that a utilitarian statement, by saying that "really like" means "valuing", but I think it's much deeper than that. It's pretty deep in human nature, from what we observe in almost all societies. So one could say that communism is literally contrary to human nature. You might be able to make it work, but you need different humans than the ones you have.)