I've never understood why the fact that striving for communism reliably lead to disaster can be used a defence of communism. Can you explain that line of reasoning? It seems to me that's saying nothing more than "The utopia that I imagine is fantastic!". The main contention is not the qualities of the imagination, but the clash between the imagination and reality.
Simply put, it can never be implemented because perfect Communism would mean absolute genocide for the nation that manages to pull it off. All variations of Socialism function by extreme, persistent violence, to enforce the state's control over most aspects of a person's life including particularly economically (and everything else as a consequence).
The closer you get to implementing this fantasy Communism, the closer you get to death. That's why nobody can do it, it's why nobody ever has, it's why nobody ever will. It requires a staggering amount of aggression and violence to even attempt Communism, much less these idealized versions (which require 24/7 perfect violence to be applied to disallow even the slightest step outside the framework by the population).
