Or, to put it another way: your criticism is tacky and vulgar. Perhaps what you're describing is "cosplaying" but that's not how immigrant communities see themselves. I do in fact know the perecentages of my national makeup but pizza and beer aren't how I celebrate that. Nobles know their ancestry down to the smallest detail, is somebody really tacky for knowing that technically they are 1/4th Italian? I don't think attacking somebody's identity is ever fair; it costs you nothing but is everything to them.