Once I was watching a movie about the Mafia, narrated by a Mafia wife. She was lamenting the fact that they couldn't or didn't associate with anyone outside the group.
Then she got to the part that reminded me of conventions. She said something like, "We even went on vacation together." The assemblies used to be a way to soak up dubs' summer vacation, but, to give it somewhat of a positive spin, it might have been the only way many of them would have visited another place. At any rate, it took away any opportunity to be around non-dubs on vacation.
Organized religion, particularly cults, and organized crime have a lot of similarities.