Good thread with St. Patrick's Day coming up...
That's the power of movies on popular culture: you mention a stereotype and within a few years everyone swears its true...I'm about 50% Irish, not that it makes any difference this is just an uninformed, unsubstantiated generalization, just like most of them.
By the way, although it doesn't offend me personally (I think everyone should be fair game equally), I do think its kind of funny how its socially acceptable and not politically incorrect to blatantly imply that the Irish are inherintly inferior (drunk, small-dicked, violent...). How did that come to be anyway?