It's not Americans doing these things. I've met plenty of Europeans with exotic identity claims, romanticizing some past culture instead of the living culture around them - Viking metal rather than folk music, to put it like that (there are also of course responsible ways to enjoy exotic metal genres).

By making it into Americans vs. Europeans you're doing a bit of what you're criticizing yourself. Yeah sure, we all agree someone walking up to you and saying they're Saxon is embarrassing, but that sweet old lady from Minnesota who's done rose painting (a national romantic fad around the time her ancestors immigrated) for 20 years is part of a living culture, which isn't simply "American", even if she has outrageous Norwegian pronounciation and otherwise isn't someone you'd like to identify with.