I know at least 5 Pharo users, and one of them wrote a book about it (for the other 4 :P). They were part of a research group at university and made us students use it. I get why it's nice and all, but honestly it feels a bit like Crossfit, or Vim. There are a small handful of excited users who try to convice everyone else how amazing it is. (Sorry, Oscar et al.)

Learning vim motions is legitimately amazing, and well worth the effort, even if you never use vim itself.