I've been rejected at a Chinese restaurant but writing something like you did: "If they don't want to serve whites food in exchange for money, they're welcome n

I've been rejected at a Chinese restaurant but writing something like you did: "If they don't want to serve whites food in exchange for money, they're welcome not to do so. In a few more generations, no one will eat that food anymore." would be inappropriate. Putting everyone in a racial group in a bucket for the behavior of one and condemning them to non-existence is a bit too far. You couldn't do that to any other group without a bit of outcry.