This sounds exactly like what one of those moderators would say...

I have observed a lot of the behavior of what OP is referring to, and I really have to agree with them although apparently some people are taking issue with it.

I think there are a lot of factors that play into why those communities are not replaced and/or people don't move, such as:

  - most users who are not regulars are transient help-seeking users that never stay long, often just leaving after being abused by the regulars for daring to ask a question

  - most regulars simply don't care enough or are enabling/participating in the same abuse to do anything about it

  - it's not something that happens constantly all day, so nobody feels it's worth trying to start up a whole new community over it, plus they don't want that burden

  - it could be argued that libera as a whole would also not be the right place for a new community due to the attitude of their network operators