Actually that analogy doesnt work for waiters or bar staff at all unless the waiter you're tipping also made the food for you or the bar staff brewed the drink. You basically just talked yourself out of tipping people in the catering industry.
Exactly. If the food tastes really good, do you get out of your seat, go to the kitchen and slip some change into the chef's pocket? No, you may ask someone to compliment the chef and that is all.