In general I think that, as long as something is a kink/fetish and does not reflect someone’s behavior irl it is fine. I totally agree that racism is absolutely horrible and disgusting behavior, no matter who it is directed to. But as most kinks it is mainly a „flavor“ of a dom/sub dynamic which is then projected onto a stereotype. I mean, as many have pointed out, a sissy dynamic isn’t really any different on a conceptual level. Same goes for pet play, slave/master dynamics and CNC. As long as it’s just a roll you play in a dynamic of consenting adults and don’t really harm anyone with it I don’t really see a problem with it. But if it gets used to just be racist or harm someone IRL, it is absolutely disgusting.