Cultural appropriation for people who don't believe in cultural appropriation
"Cultural appropriation" is a controversial topic[Citation needed]. It's one of those topics that cause many people to roll their eyes, and many others (on both sides) to lose their goddamned minds. But, there are (at least) two kinds of cultural appropriation: a silly one and a useful one.
The silly one is (at least partly) a strawman imagined by opponents, either on purpose or through lack of knowledge. It goes something like "White people shouldn't cook (or eat) foreign/minority food, or wear foreign/minority hairstyles, or wear foreign/minority clothing styles, or learn foreign/minority languages, or use foreign/minority slang, or practice foreign/minority religion. Ever. On pain of public callouts and harassment. But, any minority/foreign person can do the opposite with impunity because of white privilege and stuff.
I call this silly because it is. Opponents of the concept of cultural appropriation (or the merely confused) imagined up some of this because it makes the concept more ridiculous, but it wouldn't take too much googling to find people in the social justice world who believe some/all of this fervently.
It's "silly" because it treats a person's ancestry and race as the most important feature a person has, and this feature grants or denies a person's use of cultural artifacts like slang, food, and clothing based on perceived race or ethnicity. It ignores individuals in favor of the group. It's kinda racist group-think and full of squick.
Many people who are repelled by calls of cultural appropriation are reacting to this group-think: "Are you telling me not to do something just because of the color of my skin? I thought going by skin color was wrong?! Go to hell! I wasn't going to wear dreadlocks, but I am now, just because you said I can't!" (I'm not saying they all think this: some are just racist jerks, yes.)
The useful concept of cultural appropriation, however, just says: It's kinda rude to treat another person's culture as a fashion statement. That's literally "fashion" as in clothing and hairstyles, and figuratively "fashion" as in trying to seem cool by adopting parts of a culture you are not a member of.
The level of "rudeness" depends on many things, and yes, part of it is whether you are part of a minority or not (more on that later).
I think we can all agree it'd be rude for an able-bodied person to hop into a wheelchair and "pretend" to be handicapped to seem cooler or gain sympathy? Similarly, it'd be rude for someone with no real belief in a specific religion to insincerely adopt the trappings of that religion. And yes, it'd be rude for an outsider to superficially adopt tokens of someone else's sincerely-held cultural heritage.
If you're some white woman from California and you've read an article featuring Indian women and like the look, you probably should think carefully before rushing out to buy a bindi. Not that you can't, but to Hindus and many other Indians, the bindi has a religious significance, so some might consider it rude for a non-believer to use their religious symbol as a fashion statement. Kind of like a Christian might think it rude for a non-Christian to wear a cross necklace because it "looks cool".
It's important to remember that this doesn't mean it should be forbidden, just that people from that religion/culture might think it is rude for you to insincerely use their religious symbols, and may feel compelled to tell you so. You are certainly free to ignore them, but you shouldn't be surprised that they are annoyed with your careless and irreverent use of their sacred symbols. That said, you are free to not care about the offense they take (or even relish in it if that's your cup of tea).
In my mind, the "insincerity" and "superficiality" are key to the idea. Some white person who runs an herb shop and uses a few Ganesh statues and sitar music to make her shop seem "more authentic" is being rude, but some white person who runs an herb shop and uses a few Ganesh statues and sitar music because she's actually a Hindu is not. The white kid from the suburbs who "acts black" because he thinks it's cool is silly, but the white kid who "acts black" because he was raised in a majority-black neighborhood is not. A non-Japanese person who runs a restaurant which sells Japanese food is OK, but when she brings in kimonos and Geisha make-up, it might be considered a little rude by some.
You don't have to care about their offense, of course, but you shouldn't be surprised.
And just as importantly, the thing "borrowed" must actually be a significant and distinctive cultural identifier. Just because some black people wore their baseball hat backwards, it doesn't mean backwards-hat-wearing is a distinctive cultural identifier and therefore off-limits to those not from the culture.
Though I've used "white person" a few times (and contrary to "popular" opinion), it does not apply only to white people (but some caveats later).
When Snoop Dogg got a little too high while touring Jamaica and decided he should become a Rastafarian reggae star, he culturally appropriated Rastafarian culture. And when some black kid from a 4rd-generation wealthy family listens to few rap albums and decides to dress and talk like the "inner city kids", he's just as guilty of cultural appropriation as his white friends who does the same.
Of course, though, it is easier for the majority culture to ignore the minority than the other way around.
Trivially: if you are a life-long participant in "biker" culture (as in motorcycle "clubs"), you are not going to be too impressed by some weekend-biker rich guy who buys expensive leathers to superficially mimic your lifestyle. Deeper: if you are part of a culture that has been legally or socially oppressed in very recent history (blacks, hispanics, native americans, minority religions, gays and lesbians, etc), insincere and superficial copying by outsiders can seem vastly more offensive.
So yeah, in the English-speaking "western" world, most issues of cultural appropriation are one-sided: someone from "white culture" superficially uses a cultural signifier of a minority culture. The other way around doesn't pack as much weight. I doubt most white people actually feel that strongly about Africans who wear suits in America: Suits are pretty much a business requirement in many fields, and most white people don't think of "suits" as an important cultural identifier anyway. But, it'd be kinda weird if someone with no connection with Africa started wearing dashikis, which are important cultural identifiers for many Africans (and some modern American blacks who realize their ancestors' culture was forcibly removed).
Once more: the idea is only that the cultural appropriators are being (possibly) rude to the people of whatever culture or religion they are "borrowing" from. The cultural appropriator is not obliged to care, but they should not be surprised that some people are offended by superficial mimicry of something that is deeply important to them.
I mean, I think I'd look really cool if I started wearing a turban and carrying a ceremonial dagger, but I'd feel bad about doing so when I went to our favorite Indian restaurant which has a Sikh owner. Even though he does not wear a turban (at least at the restaurant), I can imagine he'd feel rather uncomfortable with my wearing something so important in his culture as a mere costume. If I had converted to Sikhism, though, there'd be no problem.
That's the rub, though, isn't it? On casual observation it's really hard to determine whether someone is sincerely using a cultural identifier or just trying to look cool, which is why I'd never call out a stranger on it even though I do think it's rude. The "silly" version of cultural appropriation attempts to get around this by going by (perceived) race alone, which is why it doesn't work for me.
Bottom line: Should a white guy wear dreadlocks? Fuck if I know. You be you.