It's easy: not tipping gives you an extra 18% of your dining out budget that you can spend on hookers & blow.

Better minds that I have talked about the quest for purpose in the absense of faith and I choose deliberately not to endorse any particular moral goal in this piece. selfish utilitarianism (is this really any different from hedonism?) is a good a goal as any although it's not one I personally choose as a moral end goal.

The crux of the argument is not about how you should act but you how you should fight your own moral revulsion when deciding how you should act.