[Anders would probably only be happier with Johto itself if it didn't take away his magic, but that probably isn't the case for all Thedosians.]

He doesn't like being idle, for one -- he's very resolute, always looking for people to help, rights to wrong. He wouldn't know what to do with himself.

As for keeping Pokemon... I had a cat around the time we first met, and he accused me of enslaving it. [Okay, maybe the mental image of Justice being forced by the powers that be to cope with "owning" an animal is kind of hilarious to Anders, and he even smiles a little, if bitterly.] No, I don't think it'd suit him.