I think it’s also easy to see when you’re familiar with some original thing that’s been appropriated across cultural boundaries, the appropriated thing becomes more ubiquitous than the original, and people from the other culture don’t realize where it came from. It doesn’t have to be in bad taste for people to find it grating.

Hallowe'en is like this. It's Irish, but then Americanised Hallowe'en is pushing in.