I loathe "customer" because the change from "passenger" was such a nakedly transparent and undisguised instance of changing the name of something to make people think it's better without actually bothering to change anything else (you're customers! You're always right, and that! You get customer service! - just like calling Windscale Sellafield to make people think it's not radioactive any more, etc) - and of such an oily mendacious Thatcherite yuppie kind. It was so blatantly obvious that only a fool could hear the news and ascribe any genuine positive significance to it.
If it had always been "customer" I might simply accept it as normal, but as it is I can't hear the word on the railway without still visualising it being delivered with a hideous coked-up yuppie rictus grin, nor without still being annoyed at being taken for a fool by parasitic marketroid arseholes.