I find some comments bizarre here.
I think it's because of my upbringing, but I would not dream of referring to an Irish person as 'Paddy' (unless his name was actually Paddy) or a Scotsman as 'Jock' (again, unless...etc).
I wonder whether this is merely an age thing?
I don't know of any 20 or 30-somethings in my office who talk like that, and to be honest, I only ever really hear people 50 plus who resort to '70s talk'. Is that it? Is it just down to specific upbringing, and the people who we hang out with?
Perhaps political correctness and the use of accurate terms is something I never have to think about, because the people I work and socialise with have been brought up differently?