By the time twickster moved the thread, three posters had said they wanted to respond in the Pit. I think that’s a good indicator that a thread should be moved.
When a thread is moved to the Pit, it’s isn’t babysat. If anything, it’s the opposite. It’s going to get the least moderator attention in the Pit because personal insults are allowed there, unlike the rest of the site. I also don’t think a move to the Pit (or any thread move) is a comment on the intelligence of posters or their ability to contain themselves. Sometimes we think a thread is just not in the right forum given its subject matter or tone, and that can include the kind of responses it is getting or is likely to get. A thread started in MPSIMS about tossing a cat out of the house (and other un-regretted actions) is probably going to get moved to the Pit. A thread started in the Pit about the wonderfulness of kitties is probably going to get moved to MPSIMS.
This does happen all the time. Gfactor is pretty vigilant about it.