So i've been picking up on some forum threads and news articles about this phenomenon in the last 2 years and I am just baffled by it. White people with dreadlocks being expelled..... I've seen the articles where wearing a kimono is being seen as imperialistic towards Japanese..( I think that actually caused me permanent brain damage) and today I saw the whole Martin - Lin idiocracy......
I luckily haven't encountered this phenomenon in The Netherlands or Europe (yet). In our lowlaying dikeloving country "cultural appropriation" is generally seen as something very positive. It's mostly appreciated by minorities and majorities alike and seen as openess, cultural interest, an enrichment, understanding and promoting/ cultural intergration. Most minorities even see it as some kind of validation, "belonging" when cultural phenomenons get popular and embraced by the general population. Like the Surinames and Indonesians are actually proud of their foods (which are basically seen as about as Dutch as boerenkool these days) wearing a typical cultural garment will most likely get you into a nice conversation with said minority about the garment, their culture and country instead of anything hostile.
I know race is much less an issue in western Europe compared to the US, but sometimes your cultural trends jump the pond and pop up in a "light" version over here. I'm just trying to wrap my head around why this can possibly be seen as something negative.
The basic idea, as I understand it, is this: The original European explorers/colonizers sailed off from Europe and found the rest of the world they didn't know about. In doing so, they met and then eventually became imperialistic against the various peoples and cultures, and in doing so, stunted their development and took their resources and all this (this might seem irrelevant to what you're asking, but I think the roots of the phenomenon is based in this). Note also that, to many who would argue there is "cultural appropriation", it is primarily, if not completely done only by whites (because Europeans were the primary colonizers/imperialists, but hardly the only ones; but here in America, we leave about European exploration far more than any other. No mention of Zhang He's voyages from China, for instance).
So I think, consciously or not, modern individuals who argue that whites are culturally appropriating are thinking of the old days of imperialism, and it's just become modern imperialism. The argument is we're taking what these other native peoples have, taking their culture/history and making it into our own. The idea is that members of a particular culture can engage in that culture's style and their food, dress, customs, and so on, but if you are not a member of that culture, you cannot.
It's also worth noting the arguably racist position of people who argue there is cultural appropriation. A white child who grew up their entire life in Japan would still likely be accused of appropriation for engaging in Japanese culture, even though that's all they've ever known. The problem here is that their white - their motives, history, individuality are all irrelevant to the color of their skin. Their skin color supersedes all other considerations.
Finally, the reason why those who accuse others of appropriation would almost never accuse a Japanese or black man of appropriation of white culture is that many of these people do not believe that whites don't have a culture. Doesn't matter where you come from and where you grew up or what your values are. All whites, everywhere, are responsible for the imperialism of the past of their group, and so all members of the "white" group should acquiesce to others because they are the ones in power and responsible for the ills of the other races, so all whites are the "oppressors" and all other groups are the "victims".
I think this is what happened with the Martin-Lin thing. Because Martin has probably heard this some and thought about it and agrees with it to some extent. So he sees someone with dreadlocks (a traditionally "black" hairstyle), and thinks, "Oh, that's someone appropriating my culture". So he wants to speak out about it. He does, but comes off looking like a complete asshole because the whole thing is dumb as shit. All the while he's got Chinese tattooed on his arm, and the reason he probably didn't think about it was because no one has ever called him out on it. He's a black person, therefore a member of the "repressed, victimized" class (never-mind that he will have infinitely more money, power, and influence than someone like me, despite my white skin), no one would dare to call him out on appropriation.
Does that help?