I'm gonna try to help out with this since a lot of people are either focusing on the wrong things or mistakenly believing in some shizz.
Cultural appropriation has nothing to do with skin color or a specific culture. A white culture can appropriate from another white culture (Brits from Scots for instance). The key point and defining characteristic that everyone continually misrepresents and keeps missing because they're either not paying attention or willfully ignorant, is when a DOMINANT culture who is in control of the country/city/whatever's society and culture takes something from a MINORITY culture. And if the word MINORITY is what's getting you hung up, it's because they're using the straight up definition of it as in "the one that isn't made up of the most people in a society" which in the US is black people, latinx, Asian, etc.
So in America because WHITES are the dominant culture, they're the ones who perpetrate it on MINORITIES in America. IN AMERICA. They are the ones who have the ability to take from those cultures, use it on their own and not suffer the problems or cultural removal that the minority has to suffer. So a white dude with dreads not suffering from the same stigma as a black person with dreads as well as the lens that the dominant culture separately views them through is what makes it appropriation. Taking the cuisine of Latin immigrants to this country who don't speak perfect English, who can't open spotless and beautiful restaurants, who can't open them in the "good" parts of the city, who can't afford the advertising to promote them and then using the money your dad left you to open a Latin food restaurant right in the middle of the financial district with beautiful chandeliers and a live band and hiring white chefs to cook food that you were inspired to open because you really like burritos and then slapping "Authentic Latin cuisine!" on the front of your store is appropriation.
The reason American cultural appropriation shows up so often is because the lines are the clearest and easiest to see; we do it based on skin color for the most part. It's the biggest visual key for how we appropriate things.
So to take an example, why didn't Japanese people in Japan care what was going on with Ghost in the Shell? They weren't the ones affected by it! They weren't losing parts to white people, they weren't passed over in casting because they looked "too exotic", they weren't called unrelatable by focus groups, they weren't struggling to make it in an industry IN AMERICA where they have to put up with stereotypes and white-washing and all the garbage that Asian-americans have to deal with. Japanese people aren't a minority in America if they're in Japan so Japan doesn't give a fuck what we do; they are here though so the people who are being taken advantage of are the minorities HERE.
What's this whole diatribe about? To show you that it's not inherent racial attributes that matters, it's the power dynamic and who is in the minority.
Forgive my examples if they are not specifically accurate when it comes to certain things because I am not from these cultures. But even with the particulars perhaps being incorrect the genera l thrust of my point should come across from it.
So let's take the example I said above of English people taking something from Scots. Say that Scottish people are a minority in England and England frowned on kilts. And then suddenly some English so and so in high society wears one and they are SO BRAVE and trend-setting. And kilts are now in fashion! Kilts are worn by Brits everywhere, they don't prevent people from getting jobs, they don't get people beat up in the streets or called names, they don't "out" you as a Scottish person because it's okay for YOU to wear them now! But go back in time a bit and before all this if you, as a Scottish person, wanted to wear your kilt in London or at job interviews or while walking by some pubs would you receive the same treatment? Would it be okay for you to wear your culture's garments there during a time when it wasn't the fashion trend of the English themselves? Both of them are white. Both speak the same language. But one of them is still able to direct the flows of culture in their society.
Maybe an easier example. Let's take Poland. 96.9% Polish. But maybe there are bands of Roma travelling through their cities and you can pretty much just look at this website to see how hated Roma are. They're constantly driven out of places, yelled at, beaten up, generally looked down upon. Maybe they are derided for the music they play, maybe it's too folksy or uses an accordion or whatever so people make fun of it, they yell at them for making noise, it's considered music for simpletons and trash people. And then there's a folk revival in Poland and a man who always used to enjoy the Roma music he listened to starts playing that type of music and makes it BIG. He's hugely popular, selling out concerts and CDs and he tours around Europe and begins to beget other German or Danish artists who play Roma music, maybe taking it and putting their own spin on it. And meanwhile the Roma don't have any popular artists, still get yelled at wherever they go, are never mentioned in interviews with this big Polish artist or said off-handedly. He never names any Roma people, never does anything to stop prejudice against Roma, never really acknowledges them outside of interviews. This is appropriation.
And finally let's look at a closer example to the OP of this thread. Say you are in a Middle Eastern country and you are a man. You are a Shiite Muslim and so is 90% of the country. And your country really, REALLY does not like Sunni Muslims. They're basically second class citizens. You look the same, you were born in the same country, but...they don't believe the same stuff. You though, you've never ever been prejudiced against them. Some of your best friends are Sunni Muslims and you have never spoken a bad word against them. Hell, you regularly eat over at your best friend's house and love his cooking. It's really popular among the Sunni community and they have to make it themselves most of the time because restaurants that serve it don't get good business. And if they ask for it at regular restaurants then they get weird looks or told to leave or to order something else. Your friend is comfortable with you coming over but he's had people before who have looked down on him for it before or reacted poorly because it's made with cheap ingredients and whatever he manages to get from the market. You love it so much YOU start making it! And man, you love it so much you want to share it with the world! Your friend is not sure about this and doesn't want to join you on this venture. But man, you just...you gotta let people know! So you host gatherings where you make this food and people think it's so unique and interesting! You have a pretty good job so you get only the best ingredients, maybe even put your own spin on it! Bring some into the office and it's a hit! You get know for making a mean dish and even some friends try their hand at it. But all this time, no one's called you poor or dirty, no one acted disgusted when you fed them it, all the recognition you got was free and clear! And it was for YOU.
As I said, some of the particulars may be off and for that I do apologize but I think this might help people understand this a bit more instead of defaulting to believing this kind of shit only happens in the US. It's more obvious here because of our history or the demographics of our population but if you're in a country like Poland where 96.9% of people are like you and you say you've never heard of this being a problem in your country...do you really think you'd ever hear about it from those 3.1%? If 96.9% of the population controls the way information is spread and regarded and treated?