No, kitchen staff are not being paid the $2.63/hour that serving staff are, but all included with tips servers/bartenders probably make upwards of $30-50/hr while cooks/dishwashers are making <$20 - so these type of fees are a good way to show appreciation to employees who often come in much earlier, work much later, and inn many cases work much harder for less money.

It is not their fault that you don't get paid well, or that it is illegal for you to be tipped (whatever it is that you do) - so it's pretty petty to hold that against them. There is no bait and switch (when the kitchen appreciation fee is actually being used as intended) the extra money is simply split and paid out to back of house staff in their paychecks.