[Z]

I feel like it would be like a waiter coming over to your table and telling you it's rude to put your elbows on the table and he won't give you your food until you take your elbows off the table. It's not his place to say that and the customer would probably complain that the employee is refusing them service on unreasonable grounds and of course the restaurant would formally have to support the customer. It doesn't make the waiter's comments incorrect, but the course of action is inappropriate.