Comment by nck4222

I think that's exactly what he's saying. The top leave because they realize they don't receive any benefit from interacting with the community, until finally the only people that're left are the ones that are unaware.

"Each layer of disappearances slowly reduces the average quality of the group until such a point that you reach the people who are so unskilled-and-unaware of it that they’re unable to tell that they’re part of a mediocre group."