My son (may he rest in peace), and his ex (may she never have any peace) were waiters. It is a very very tough job. 75% of their income is in tips. To not tip, is about as low as you can get. Those people are on their feet non stop. They are at your beck and call (for the most part). A non-tipper, and/or a poor tipper should be ashamed of themselves, ESPECIALLY one who makes a very good living.