I have a good friend and shooting buddy who also happens to be my barber. He told me a story that your post brought to mind.
He had a regular customer who was never satisfied with anything. He constantly b*tched about the service, the price, the wait time, and mostly, about the haircuts he was getting. He was always complaining that the haircuts were crappy, that he could do a better job cutting his own hair in the mirror, etc., etc., etc. Well one day my friend just wasn't in the mood. Joe Customer came in the door and started right in complaining about the last haircut he had gotten. My friend lit into him. He told Joe that he was tired of listening to him b*tch and that if he didn't like the haircuts, then he was welcome to take his business elsewhere. Joe smiled real big, said, "I wondered how long you were going to take it", and became one of his most friendly (and favorite) customers - not to mention a good tipper.
I can't imagine anybody intentionally doing something like that in their M, but do you suppose...