Climate change deniers are bad, but literally denying the slaughter of millions of people is straight up ridiculous. Denying climate change is bad, but the holocaust is a much more emotional issue.
I agree, holocaust denial (and genocide denial in general) is far worse, creationists don't really affect actual scientific research anymore so it makes no difference, believe what they want, CC Deniers are bad, but I don't think their motives are morally reprehensible at least, they just buy into some junk science and excuse making, but I think most are tricked.