Define "treat opposing fans bad"? There is good natured heckling, and then there are the knuckleheads who have their beer muscles pumped up before they even walk in the stadium and are looking for an opposing fans whether they are minding their own business or not.
If you don't think the out of control drinking in the lots carries over to the stadium, you are living in a dreamland.
That being said, the same holds trues for some of the opposing fans who come in liquored up looking for trouble. In that case, you won't end up seeing the end of the game nor will the Bills fans who can't find a way to turn the other cheek.