You are asking a slightly loaded question, if you don't mind me saying so; the question of "evil" is really more of a philosophical problem than an historical one, and there are plenty of historians who would argue that labelling anyone, even Hitler, in this way is troublesome, not least because it offers an "out" to the rest of the many thousands of people who played a part in Nazi crimes, before and during the war, and, especially, played a part in the Holocaust.

Anyway: there is always more to say, but, if what you're asking is when Germany, or when the Allies, became aware of the Holocaust, or when the topic became fairly commonly discussed in schools and general public discourse, u/commiespaceinvader's work here at AH is an excellent place to start while you are waiting for fresh answers to your question:

To what extent was the German population aware of the atrocities of the Holocaust?

When did Americans, and the rest of the world, discover the atrocities towards Jewish folk during World War 2? Was it known about prior to our entry to the war, or only discovered after reaching Germany and happening upon it during the campaign?

"In the 70s the holocaust was rediscovered as a uniquely European/western european burden" Can someone unpack/expand on/evaluate this statement?

If you're genuinely interested in pursuing the more philosophical aspects of the question, however, Hannah Arendt's Eichmann in Jerusalem and Tony Judt's discussion of Arendt's thinking in his essay "The 'problem of evil' in postwar Europe" are standard places to begin. In his essay, Judt discusses two problems that all historians need to be aware of. One is the issue of ‘making waves’ – arousing controversy by airing unpopular opinions. The other is the question of what happens to history when it concerns itself with ethics, morals, and rendering judgement on the past.