Hitler has become the universal symbol of evil for the world.
He is a safe target because the entire world basically fought him, so declaring him "evil" works politically for all those governments that fought him.
However, Hitler was not the greatest evil at that time, Stalin was as he murdered millions more than Hitler. Stalin even helped attack Poland when Hitler did as Stalin and Hitler split up Poland between themselves, but war was only declared on Hitler. However, Stalin is not seen as a universal evil like Hitler, so why? It was because he helped fight Hitler with the rest of the world a few years later when Hitler invaded Russia in 1941., so how could the rest of the world paint an ally as evil?
And then came Mao who murdered even more people than Stalin, but the world refused to declare him as universally evil because of the Marxists in the world that supported genocide Joe Stalin
In fact, Marxism has murdered hundreds of millions more than Hitler ever did, yet today the media paints them as "cool" and posters on this site routinely defend Marxism in a roundabout way. Even the founders of Black Lives Matter were self-declared Marxists even though Karl Marx was an open racist and though blacks an inferior race.
Marxism has taken over the media and academia to hide their dark history and then uses Hitler to compare all their political opponents too using the media and academia. Now half the US is convinced that the greatest evil in the world are their political opponents who are all Nazis and not the wrecking ball of Marxism that history has shown to be the greatest threat to freedom and life in general over the last century or so.
This is the main reason Hitler will continue to be pushed in your face in the media and academia. It is because everyone requires a savior and a devil to fight. For the Marxist, their savior is Marxism and their devil is everyone that opposes them, just like Hitler did at one time even though Hitler and Stalin were basically cut from the same socialist cloth. After all, the term Nazi means National Socialist.