You disregard the capacity of humans being evil under every regime. I mean you can have a few good men wanting to create a nice Communist utopia, but eventually a lot of evil man will take the power and use it in their own advantages. Every Communist implementation suffered from the same problems. Not only that, but because most Communist implementations were authorian in nature, the corrupt leaders in power had more tools to be evil.
People should become more enlightened and they will naturally desire communistic society. Until then, I guess we are stuck with this.
Well, without a magically enlightenment any communism implementation will fail again and again, repeating the same failures of the past. Some people are arrogant or naive enough they will do a better, everlasting communism if they had the chance. History shows us the degradation of the initial values will follow. That's my opinion.