[Cherry Christmas]

I think Joe likes to be top dog, he has gone in to be the father figure, Raph and Arthur didnt let themselves be influenced by him, he probably hates that Raph didn't join in the Arthur bashing, as he probably knows now that Arthur has left that it went to far and it mightn't look good from a public PoV. Also I think he likes to be complimented and adored and maybe some of the HMs are not bothering to feed his ego