Just because most people are wrong doesn't mean we should encourage the dilution of words.

I might be sympathetic to this argument if the severity actually differed, eg. people calling mean tweets "violence" or something, but that's not what's happening there. I don't see any meaningfully difference between "I'm discriminating against you because you're Chinese" (culture/nationality) and "I'm discriminating you're Han Chinese" (ethnicity). I doubt the average racist actually knows the distinction between the two anyways, and I doubt people are going to be like "oh you're discriminating based on culture instead of ethnicity? I guess that's fine then!".