I can't completely blame them as I am sure they get a lot of arguments from customers that are over the top making no sense at all. But as long as they listen they should be able to determine when someone knows what they are talking about versus making things up to support their argument.
What I have seen here is that some moderators will assert a position. The customer might argue that. It is here that the moderator _should_ go and check and verify that they are in fact right. What has happened is that the moderator keeps asserting incorrectly and thus the problem gets escalated.
Far too often, I might add :-\