Farewell threads aren't particularly well received. Anyone who's been here for a while has seen this sort of thing happen repeatedly. Someone gets pissed off about something, wants to give a parting shot, or simply wants to say "goodbye", posts a goodbye thread, and gets torn apart by the membership.
The people mostly come back within days. In one particular instance, mentioned in this thread, the departed returned and started posting again in the same thread. Funny stuff, to me at least.