Both. Ben's taking off for personal reasons (it's literally written in his email, but people will still try to pretend it's related to the recent kerfuffles with Red Hat)
Redhat dose some questionable stuff, especially all that union busting bs but it's far from the worse employer and if you love foss you probably do something you love there.
I agree, I am certain that there are thousands of great and passionate about FOSS people there. I'm just not that certain about IBM ;) It's still probably better place to work at than most.
All in all, I am only saying that the fact that somebody cites "personal reasons" doesn't mean there are no other factors at play.