@Walter Hinteler,
I think it's a cultural thing, in a land of immigrants they all seem to need some way of expressing their individuality. It's strange to us, but what's quite disturbing is that they all seem to think that we should automatically understand their strange quirks, and that the rest of the world thinks like America.
Being English makes me a mongrel anyway, up to 1066 there were Celts, Romans, (and other denizens of said empire), Germans, Dutch, Norwegians, French, Danes and Swedes all making up what is England. That's not including the thousands of immigrants from all over the world that have come over here since.
It's a lot easier just to say I'm English, regardless of what diverse nationalities form my genetic makeup.