I think the reason why the idea of "cultural appropriation" is so prevalent in US culture is because of the long history of white supremacy/colonizing theft in this culture, which is based on the Capitalist model of monetizing anything the dominant culture can get its hands on. As a result we sometimes don't take into account that that may not be the case in the different Asian cultures.

White people in the US have a long history of stealing cultural artifacts from us while denigrating the cultures those things were stolen from, as a result, a lot of Black Americans have developed a very protective (and gatekeeping) attitude towards the things we create. We are not calling things cultural appropriation for the fun of it or because we wish to antagonize. We do this because the things we create here are regularly mined for profit, from white people who don't make any effort to create their own stuff, and who then turn around and denigrate us for having created the things. Its all we've ever known! Its unusual and baffling to some of us that other cultures would find the things we create admirable, beautiful, and exotic, and just want to participate in it. The vast majority of Asian people (unless they are born in the US) don't see Black people every single day. To the Japanese, Chinese, Koreans, etc., we are like the people they see in movies and on TV.

Unfortunately, our attitude carries over onto other groups of people who genuinely admire our cultural artifacts and simply want to participate. Black Americans are unused to having thei things we create openly admired by non-Black people, because we have been so subjected to white people denigrating us as a people, while stealing the things we create. (It gets complicated.)

I wrote about this in one of my blog articles about how white culture in the US is about stealing and monetizing whatever can be mined from other cultures within the US rather than creating their own. We call these people "Culture Vultures" and it happens so often that its hard for us not to see this in every group of people who see us as worthy of admiration, and see the things we do as beautiful and exotic. Our go-to reaction has always been to take offense and gatekeep, not understanding that in other parts of the world what we are seeing is genuine admiration rather than stealing.

This issue also sits uncomfortably side by side with anti-Blackness within Asian cultures, some of which comes out of white supremacist culture in the US.