In reply to Durbs:
Indeed, your post pretty much says / elaborates upon what I was getting at. I think we would have had Foo Fighters or similar what with Grohl being a guitarist at heart and almost just "jobbing" as a drummer. Might have started later but as you say, Nirvana were not going to be churning out albums #5, 6, 7, 8, 9, 10....
I'm sticking my neck out a bit here as I am not a devotee and don't know all the songs (don't know 25% of them!) but Nirvana's success meant that Cobain was running out of material - biggest rock star in the world can no longer wail about isolation and desolation, and if his health had improved, then what? Go political. Eddie Vedder had that covered, probably...
So. Voice for hire. Supergroup stuff like Audioslave, probably - and there you've already accurately said "fewer still went on to work on successful new projects."
Post edited at 13:34