Everytime this discussion comes about i think we lose a bit of scope of what the ethos mean and what the policies represent.
Collectivist/Authoritarian, especially the fanatic kind represent everywhere from a dictatorship in human terms, to a literal hive mind where pops are nothing more than semi autonomous apendages to a queen (Enders Game Buggers).
Communism in the human sense can be Egalitarian OR Authoritarian.
EDIT: Furthermore, the game is much more focused on Sci Fi than actual historically correct terms. Instead of comparing to real life governments, the ethos are supposed to drive us to sci fi universes. The rules and mechanics must simultaneously support :
Xenomorphs, Predators, Star Trek Federation, Star Wars Republic, Star Wars Sith Empire, Enders Game Buggers, Starship Troopers Federation (both the movie AND book), Mass Effect council, etc. I for one think it's a tall order and am satisfied, for the most part, with the outcome.