Yes, that is one big difference. Coercion is the problem, not that Christian churches have not engaged in the practice (the Inquisition).
But even when it is voluntary such as the kibbutz movement in Israel or the Jamestown colony, it is hard to get it right.
I think it is very important to study communal societies because under some circumstances such as new colonies with minimal populations in remote places (like Mars perhaps), it may be what needs to be done.
Notice that you very seldom see leftists pointing to Hutterites as an example of successful communism. They just can't bring themselves to admit that dedicated Christians can succeed where atheists fail.
Thanks for an even more excellent post!
Anyway, I gotta go. On another thread, FastCoyote is caught in a whirlpool of doubletalk and is using his miracle underwear to get out of it, while God-Guy laughs at his predicament from the planet of Kolob. I just gotta see how this turns out!