to be fair, I feel like that's something Twelve might say to anyone under the age of twenty (or Ten, for that matter, "happy slappy hoodies with ASBOs," was, I think, how he put it...), but the casting connotations were... unfortunate.
I think that's one of the recurring problems the show has, is that they assume that because the Doctor is pretty much equal-opportunity rude and condescending to everyone when he feels like it, that they don't have to consider the implications of how it will come off directed at specific people.