Meh, this isn't a matter of what kind of cup people drink out of, it's a matter of cut the idiot off if he starts to get drunk, which any good bartender will do. I mean Hell, if your gonna take all glass out of a bar to keep people getting broken glass embedded in their flesh, you might as well take out all the chairs so no one will get one smashed across their back. Hell, take out the bar itself, so nobody can get their face bashed on it.
See? Doesn't make much sense when you look at it that way, does it?