could be so socially unaware that they would make a malicious comment to a stranger (especially one he's opening will give him money).

Saying something that is stupid is completely different from saying something that is malicious.

It seems most of the disagreement in this thread probably arrises from our own interpretation of the maliciousness of the statement. For those who think it's malicious, they've chosen to fight fire with fire or to punish what they perceive as malicious behavior.

For those of us who think it's banter (or just immaturity) and think that most likely the waiter was hoping to get a "Yewts suck" and smile in return for his comment - we think that fighting with fire a comment where no offense was meant (or where it's just a kid saying a stupid thing) would be a overreach and cause more harm than good.