Originally Posted by
Whirlzap
It's bannable based on the reason of personal greed.
If you boot him at the start of the game, it's fine.
If you boot him at the boss fight, it can be bannable if it's for a bad reason such as you wanting all the pinks or he is too low level.
You are ruining his experience by doing that.
HOWEVER, if he is not doing anything or just making Aunt Emma resetting her HP, then this player is ruining THE WHOLE PARTY'S PLAYING EXPERIENCE and that gives ample reason to boot him.