True, if you want to shit talk the crowd, its best to do it in a charming manner like Chael Sonnen. That and the fans booing isn't something that's personal but rather its part of the fight culture. When the fighter starts insulting back, then the norm of the culture has changed and that becomes a new dynamic.
Its matter of expectation and that, the fighters are supposed to be characters who are stone cold in their demeanor and that nothing bothers them. While Colby broke that mold by reacting in the manner that he did.
I agree, Colby is not articulating anything that is silly like Chael were you know deep down you cant take serious. Or how Conor at least brings his own compatriot to the game and while he may insult a country, he will also compliment in that same breath which kind of has a redeeming effect.