The point is that everyone should do it willingly, and if they don't they're evil, or at least should feel guilty and suffer for their sins. Despite rejecting religion, communism is still neck deep in christian morality, like practically all western thought.
If everyone wants to do it, is not coercion. See, also, why Marxism-Leninism is a load of fascist bollocks, and why Marxism is more part of a philosophical, idealist, evolutionary view of society, typical of the time, than the fascist clusterbungle that Bolshevism turned it into.