Waitresses have to learn the whole menu, as well as how they are generally cooked and the ingredients in EVERY dish. She has to be able to remember special request, what everyone is drinking at all of her seated tables the whole night. But most of all, she has to remain friendly to complete ass wipes and "holier than thou jerks" which she will usually get at least one of them every night.
She will have to sweep/mop up messes left by kids of degenerate parents who let them do whatever they please, and somehow think it is the wait staff's job to clean up their childs vomit.
A nurse's job is a
hell of a lot more difficult than that and they don't stick their hand out at the patients and expect them to cough up extra (so to speak). They get
paid to do their job.
Every job has many requirements. If someone doesn't want to work as waitstaff they can look for work in another area. If it's such a super-human task then the owner should pay them accordingly, or not. Don't ask the customer to make that decision for him. It doesn't have to be complicated, and it doesn't have to be a shakedown.