Most places require the wait staff to tip out the kitchen a percent of their sales at the end of the shift to the tune of 2-5%.
If you don't tip then you are actually actually taking money out of their pocket since they're now going to have to cover your 2-5% tip to the kitchen out of their own, rightfully earned, money.
That is illegal. Google it. A group of tipped employees (ie. servers and bartenders) may pool tips. But it is illegal to force them to include non-tipped employees (ie cooks, dishwashers, etc) in the pool. Servers may tip the cooks, etc themselves if they want. But they can't be required to.
If you don't tip then you are actually actually taking money out of their pocket since they're now going to have to cover your 2-5% tip to the kitchen out of their own, rightfully earned, money.