So, to be clear, I don't actually accept your premise to begin with. I was a waiter for years and never saw this sort of thing. I did see poor waiters get crappy shifts, but... well of course they did. Lacking any actual evidence I don't see where this can go.

>If you accept the notion that you get tipped less because you are a poor job performer, what is the point of laws that force employers to make up your wages to minimum wage?

The point would be to... establish a _minimum_ wage, regardless of performance. What about that is confusing?