The belief that "cultural appropriation" is offensive or even evil is hardly new; when members of one culture adopt elements of another, discomfort is a fairly common response. Yet the scolds seem to be gaining momentum. Many college campuses, including my own (where the issue is sombreros), have been the scene of "appropriation" controversies.
Poster girls for recent brouhahas include Iggy Azalea (a young Australian rapper who sounds a lot like a black American) and Miley Cyrus (who had the audacity to wear dreadlocks when she hosted the Video Music Awards on MTV). Amandla Stenberg, who played Rue in "The Hunger Games," even made a video titled "Don't Cash Crop My Cornrows" citing "rampant" cultural appropriation in Cyrus' hairstyles and dance moves, as well as Katy Perry's slang.
It's certainly problematic when the "appropriated" culture is ridiculed or the appropriation is merely stereotypical. But overall, I am in favor of the practice, and I don't think we can or should do without it. Appropriate with some respect, I say, but also with considerable insouciance.