The customer doesn't pay the salary, you do - we, the customers, provide what is in effect the performance related pay..... and like anyone else on performance related pay (with the possible exception of some in the banking industry) if you have a bad time at work it will effect your performance related bonus

I'd support the other posters here asking you to identify your restaurants so that we can be sure to pay your staff for you regardless of the service they provide, if only to avoid meeting your staff in the alley.

"stiffing a waiter because their service wasnt up to your expectations" may or may not be a "low class move" - threatening your customers because they have temerity to tip according to the service is certainly a low class move.

Finally, a lesson for you as a restaurateur, there is no need waste your time banishing customers who "stiff" your staff - "stiffing" your staff, as you call it, is one of the ways we, the paying public, use to tell you WE won't be back!