Hi!
Well, while from a factual point of view, the holocaust is undeniable history, there are a lot of complex motivations involved in trying to disregard the event. While most of these motivations can be traced back to outright malice and racism, some of these motivations may actually stem from the way earnest people are handling the issue, especially in Germany.
First of all, there is the complex relationship between the state of Israel, Jews, and the holocaust. As these three items are often linked in discourse even today (a state, a religious group of people, an event in history), often when trying to defend Israeli policies or defending Jewish citicizens against racism, in turn racists and enemies of either Jews or the state of Israel will kind of automatically consider the reality of the holocaust as something undesirable.
Secondly, the holocaust is also linked to the old tradition of European Christians to discriminate/denounce and persecute Jews as murderers of Jesus/child eaters/poisoners of wells/conspirators/greedy banking spiders. Especially the undying accusation of a Jewish world conspiracy makes people actually believing in such a conspiracy ready to doubt the reality of the holocaust.
Then, we get to the way the holocaust is dealt with. I have rarely heard that people talk about it as a social phenomenon where a group of people (most citizens of Germany and Austria back then) was led to take violent action against innocents belonging to several groups (Jews, Sinthi/Roman a.k.a. gypsies, handicapped people, homosexuals) they had prejudices about. Instead, I have the impression that the holocaust is presented as a near mystic affair of some monstrous "German Nazis" killing "Jews", which in itself is the only definition of that crime. Those nazis back then were people just like us. People like the people living in Bremen, New York, London, Tel Aviv, Bagdad today. They were not some supernatural monsters and what happened back then was not some magical battle, but an extreme example of racism and genocide which are still all too alive all over the world. Besides making people lax in their caution about racism (after all, if it isn't hunting down those mystic "Jews", it is not the same thing, right?) and prejudice, it also removes the entire event somewhat out of history. It becomes more of a fairy tale than a real event as the participants are not shown as normal humans but witches and innocent princes.
Finally, Germany itself is suffering especially from an odd way of dealing with it. Schools kind of center their history lessons around the topic and the entire discussion in Germany runs around some mystic concept of a "special responsibility" bordering on inherited guilt. However, as I said before, the psychological/social mechanisms are not abstracted and looked at in general, but it is reduced to a mystical formula with the insignia of that age having magical power in Germany making decent people afraid and cower in fear thus becoming attractive for those who have no real perspective in life. This entire mystification in Germany has something pathological and sometimes you get the impression that modern Germany has a kind of morbid "pride" in some "special guilt" that sets them apart from the rest of the world. It is hard to explain, but there is some kind of self-definition by self-condemnation going on, and it is just as perverse as it sounds.
This utilization/mystification of the holocaust by Germany and by the state of Israel probably also makes people wary of the historical facts. With so much obvious interest in stressing the enormity of the crime, people may wonder whether it was really as huge as is claimed, or whether those profitting - in some cases in a rather perverse fashion - from it are exaggerating.
Anyhow, as far as I can tell, the holocaust did take place causing the death of hordes of innocent people only because of them belonging to one of the prejudiced against groups. And since it was born of the human mind expressing human thought patterns that are all too common even today, we should remember its lesson of "Never again" and make sure that no group of people casts doubt on the humanity of another group of people. Because that is what lies at the heart of the holocaust - the claim that some people are less human.
Deathworks