Just to chime in, the other issue is consolidation of these communities by a small handful of people (i.e. powermods).
They've already started doing it here too, trying to grab all the keywords and popular communities (e.g. [email protected]) so it's something to keep note of moving forward too especially as certain instances start to see more growth than others.
That's fair but my assessment is rather than enabling that behavior, cut it off at the source by limiting the number of communities to be made per user. Sure, there'll be alt accounts, but it's better than just looking the other way and pulling another Reddit.