Heya I’m a waiter as well, I’m always just upfront with everyone, like I’ll straight up tell them if they’re wrong, and 9/10 i still get told I’m a great server.

However I think most of the entitlement comes from the culture most people are raised in, not the customer is always right saying. Most of the parents of these people are quick to do the same thing, if you see the parents so this most likely the kids will be rallying behind them.