I guess the kitchen does deserve part of tips, but part of the problem is that restaurant owners in the U.S. has tricked us all into paying a large part of the salary of wait staff. While it's technically a "tip", wait staff depend on tips to actually make any kind of money since their base hourly salary is way below minimum wage in all but very nice restaurants. On the other hand, the kitchen is at least getting minimum wage and probably more depending on skill. But, I'll confess that's it's been 20 plus years since I waited tables so maybe it has changed.