Jockbod48 saidI was a waiter in my college days - - - and a damned good one, if I say so myself.
No excuse for anyone treating a waiter, or clerk - - anyone in service - - with anything but polite treatment. No excuse. Sometimes an ass who was brought up poorly - with no education, breeding, tact or style will treat a waiter badly ... with the misguided notion that he is the "big man out on the town". Nothing cool about that at all. In fact - - - when you see really fine people, the best people, people with education, breeding and tact - - - notice how beautifully they treat the waiters or any clerk, server, car valet......anyone they meet.
I learned this from my late parents. Whose behavior to service people was impeccable, always friendly and outgoing, never condescending, but rather the attitude of equals.
My Mother in particular would get livid if she saw someone berating a waiter or some other person. "Don't you ever behave like that, Robert," she would say to me. "You are no better than anyone else, and everyone is your equal, no matter what job they hold." And she was quite serious about it, and likewise my Father, who was the most racially color-blind person I ever knew, and in the 1950s in the US, no less.
I worship my late parents, and what they instructed me. And if I am ever egotistically abusive to a waiter or other service person I know my Mom & Dad would come back to haunt me. It's simply not what a gentleman does, and not what they taught their son.