interplanetary travel works like trains (big engine moves a bunch of passive cars from body A to body B, then the cars get shuffled around to other engines to get to their next destination body C),
asteroid-to-asteroid travel works like cars and trucks (personalized, decentralized, etc)
as a result, unions have less trouble establishing themselves in deeper gravity wells;
once you get past the event horizon, all worldlines are bent to follow an inevitable historical progression towards communism which will be attained in a finite amount of time