Yes, no question. End of discussion. Silly to argue it's not derogatory. If the employee wished to use a non-derogatory term, something like "gate blockers" would have sufficed.

But what I find most interesting in this thread is all the indignation. All the same folks who use terms like "kettle" and "lounge dragon". And I'd bet a dollar there are people here who have used the former in public at a gate.

None of these terms are appropriate, whether used by a UA employee or a customer. But the best course of action when you hear them is to ignore and silently reflect on what a fool the person saying made of himself, and how often he must leave that impression with others he interacts with.