People are mad at Bruno Mars for taking advantage of his racial ambiguity to "appropriate" black culture, which suggests that people want black culture, but not black people. Bruno Mars mentioned that "black" music has heavily influenced his own music and has come under fire for making decent music. Not only that, Miley Cyrus rebranded herself and is going back to doing country. McNamara commented on Miley Cyrus's apparent hypocrisy in her reactions to rebranding, but if you try something and it doesn't work, it doesn't work. Miley knows her music and what works for her best and may think differently of other artists...and that's okay because tastes are largely subjective.
Katy Perry told a fan that the term "wig" wasn't for them (???) because they weren't in the LGBT community and one commentator on this video said that she didn't have the right to exclude someone from a culture that she wasn't a part of. Last I checked, Katy Perry is bisexual, but apparently, we don't exist unless people like this want to call us "bihets" or tell us to check our straight-passing privilege. Not only that, the commentators pointed out her hypocrisy in "appropriating" other cultures, which I sort of agree with. If you're going to preach something, at the very least, practice what you preach. That said, I still think cultural appropriation logic is not only stupid but regressive in nature.
Hard lines on cultural appropriation will not help race relations but harm them. For example, is it wrong for a Japanese person to wear Chinese clothing because of the rape of Nanking or are all Asians the same to the proponents of cultural appropriation logic because the concept of cultural appropriation itself is largely America-centric and ignores a lot of the history of international interaction? Cultures don't "belong" to people any more than memes "belong" to the creator of the original.
Part of living in a nation as diverse as America is cultural exchange happening on the daily, especially with things like Instagram where these styles come out more and more quickly. To reject this natural consequence is to reject new expereinces and reinforce the xenophobia of the past. I think these commentators just need some good garlic naan to be able to taste the goodness of organic diversity (recipe here).