Uh… what about the people actually paying the tip? How on earth is it beneficial for the person paying more money for the level of service they should be getting regardless? How is that extra $3 more important to the server than to the person losing it?

This is the crux of the argument. You’d be paying this anyway, because servers won’t take the job for less money. No matter how you slice it, you’re spending this same amount of money.