Here's a thing that's been nagging me about the whole idea of cultural appropriation, and there's a lot, it's a stupid idea out of the gate...anyway: the big deal is that it's not about culture; it's about conflating race with culture, which is kinda freaking racist.
Does Manhatten have the same culture as Bluebell, Alabama? Hell, does Manhatten have the same culture as The Bronx? If a dude from Manhatten decided to don a mullet and host a tractor pull, would he be appropriating rural Southern culture? Well...by definition, you could say he is; but, nobody's going to throw a hissy fit about it.
Keziah Daum received national ire because she's a white girl who wore a traditional Chinese dress to prom. The person who started the outrage wasn't even from the same part of China. In terms of land mass, China is the second largest country in the world. If there are cultural differences between Culver City and Orange County, I've gotta believe that there are cultural differences among regions in China.
You can call it cultural appropriation if you want; but, in action, the assumption is that these cultures are innate to race and/or nationality. To assign a culture to a race is racist. It's to assume personally and customs about a person due to skin color.
Yes, different people of different skin colors have been treated differently throughout history. I'm not denying that for a second. It would be absurd and obscene for me to do so. But, the concept of cultural appropriation is making our society more racist, not less.