The first thing a server thinks if they get no tip or a low % tip is that the customer is/was an asshole... not that maybe they did something wrong. Maybe if they treated the customer like shit they expect it, but it's a horrible tool to gauge effective service levels.
Bullshit. Most servers know the difference between getting a low tip because of a problem and getting a low tip because someone's an asshole.
..and again.. you can't escape that the system is discriminatory.
You mean despite dealing with it in every comment above? btw, ran the numbers and the black-white wage gap is actually greater than the black-white tip gap. We should totally get rid of jobs. Or replace wages with tipping, since tipping appears to be LESS discriminatory than wages.
..and yes.. the bartender one.. I'm tipping the guy so effectively he rips off his boss. That's an awesome system for owners.
The point remains, you do tip more based on perceived service. That you only tip good for shitty reasons is your problem.