Also incompatible with the way they act toward him.
Plus, Rich confirmed that they don't have players, so that can't be the reason.
Plus...I find the idea that the OotS' imaginary players are just like their characters distasteful. It strikes me as unimaginative. If we're speculating about players, I'd rather look at "why would Belkar's player choose to play a psychopath?" than assume Belkar's player is psychopathic and/or immature.