I have heard different explanations for the Holocaust

One that seemed promising to me was Judicial positivism. If you add this to ethical relativism and Nietzsche who was the prime philosopher in Germany from about 1890  and onward, then you get a powerful mix that could contribute to World War Two and the Holocaust. That means that I have sought reason for the Holocaust from the failure of philosophy. Recently it has come to my attention that there is  another more obvious reason-- anti-semitism. At some point it is possible that people just stopping thinking of Jews as worthy of life.

And the cause of antisemitism seems to me to be anti goyism (or anti gentilism). This is what I think is clearly the implication of a verse in Mishlei [Proverbs], "like the face is reflected in water so is the heart of man towards another man."

And the cause of Anti-Goyism I think is bureaucracy. That means to say some people get comfortable in rabbinical  jobs and cease to worry about the implications of their actions. So religious leaders are a similar position as a government bureaucrat. They become comfortable in their positions and cease to worry if their preaching is in any way reflective of the real world. After all they do not need to deal with the real world since they are insulated by their "shtele' [position ]. They are in that way like a government bureaucrat.

This is along way to get around to what is already stated in the Talmud [at the end of Tractate Shabat]--all problems that come into the world only come because of the judges of Israel.

 What passes for morality is in general the evil inclination dressed up in some mitzvah.  Nietzsche picked up on this theme  and held that all human morality comes from the human basement.
I do not think  all morality is from the human basement. Maybe most of it,- but not all. Some morality should be  attributed to the human attic. [The  urge to do good.]