That way of saying that the holocaust is a thing of its own, that can be compared to nothing else is simply a way of separating genocide victims into first-class and second-class victims. The only outcome would be to weaken the collective "Never again" outcry against barbary.
That's what they do in Germany. They teach it as a unique thing that can never happen again... which leads people to never question whether it could happen again... which may lead to it happening again, because any sign that it was happening again would be dismissed, because "it can't happen again" is drilled into people.
The default attitude of any human is to support the status quo, but you'd think Germany in particular would do a better job of changing that default with education. It seems like it doesn't.
Obviously, if someone was doing another holocaust, it would be in their best interests to make you think the very notion of more holocausts was prima facie completely absurd.
In Germany it's illegal to compare things to the Holocaust, even if they are like the Holocaust, even if they are literally a second Holocaust. A politician couldn't run on a platform of "we'll do another Holocaust" (they'd be arrested) but could run on a less specific statement like "we'll eliminate the useless eaters to make Germany strong, sending them Aut to Schwitzerland" and you would be arrested for pointing out how Hitlery that implication was. You might get cleared of charges by the court... six months later.
Here are a few other genocides of the 20th century: the Armenian genocide [1], Porajmos [2], the Rwandan genocide [3].
Please enlighten us on how pointing similarities in the administrative involvement, the systemic nature of the targetting, the harnessing of technology, or the way individuals perpetrating it are made to feel less accountable is, in your words, "highly inappropriate".
I honestly don't see how you could make such a claim for all these examples without negationism.
