I'm very used to engineers' quibbles, very focused views ending up being very narrow views, clever/stupid explanations of why various laws can't be enforced, and so on.
But this has the be the biggest instance of missing the point, intentionally or not, I've seen in quite some time.
> [...] and also there were events in history like china's cultural revolution, Stalin's great cleansing and the killing fields in Cambodia (to name a few) [...]
Under the assumption that is meant to be a sincere argument:
The difference between the holocaust and those crimes is that Germany's the country primarily responsible for the former, giving special meaning to the denial of that crime and the law banning its denial.