He knows it's futile to argue with Gabriel about their right to do as they please-- a right that they don't have to be given, one that they simply take because they can. It doesn't matter what universe they're in, they are beholden to no authority but their own.

"It's degrading. Haven't you had enough of slumming it, Gabriel? Pagans, humans, sapient vehicles-- you've run the gamut. You've been around every block, congratulations. Are you done now?"

He says it as though Gabriel is the token rebellious child here, and all of this is just a phase that he should get over soon enough and come back and be a respectable angel. You know, like himself and Michael.

"For someone so intent on teaching lessons, you're terrible at learning your own."