I think you are talking about ones you met who live in the US?
Well that would make sense because people from that area of europe moved to the US relatively recently. It's similar to how the Irish and Italians were very nationalistic back in the day to the point that they had their own communities within NYC.
So I see where you are coming from because I am first gen Macedonian (my dad was from the "old country"), and my family is super nationalistic and it can be kinda annoying sometimes. But you just gotta understand that thats how everyone once was.