It's not that a specific person does a specific things that's bad. It's that cultures have different takes on accepted behaviors. Some behavior that seems more or less ok in culture A, is going to piss people off from culture B. Do you stand on the left or right side of a hallway when talking down it?

At the same time you will find people going against type regularly. Which has a moderating effect. It's hard to think X are bums when you see hard working people from X.