Yup that’s why it’s a good idea to tip your server. It’s like paying for protection of your food.
If you don’t like that system, try leaving a crappy tip and see what happens next time.
Discussion
I always tip well in sit down restaurants, or at least I used to when we could afford to do that.
What I don't tip is mediocre service.
The Subway near us for example, the people are clearly just doing a job. They're not kind or engaging or even friendly and Hell, most of them barely speak english anymore. They are stingy with the toppings and they put you through as fast as they can.
I don't expect the world, but the "I'm just here for a paycheque" attitude really comes through and I refuse to tip that sort of thing.