The myth of the “Clean Wehrmacht” (I.e. the claim that only the Waffen SS engaged in the various War Crimes and Crimes against Humanity that Nazi Germany is known for, whereas the Heer, Luftwaffe, and Kriegsmarine were innocent and somehow unaware of things like the Holocaust and forced prostitution), and its various derivatives (such as the insistence that they were only forced into committing the above by officers/the SS, or that Nazi Indoctrination meant they weren’t responsible for Crimes they committed) of course first appeared in the immediate aftermath of the Second World War, but in recent years it seems to have become more and more widespread. Whenever the Wehrmacht is discussed on Reddit (NB: this is just my subjective observation, and is by no means an objective statement) and other social media sites, it seems like the supposed innocence of the Wehrmacht is brought up. The thing that really struck me personally is that it seems to be prevalent amongst people who seemingly have no obvious Nazi sympathies- you would expect it would be fairly common amongst Neo-Nazis and the like, but more and more I’m (again, personally) encountering people who appear to have been taught or otherwise convinced that only the SS committed war crimes during the Second World War. So, is there any consensus amongst historians as to why this myth has persisted? Now that the majority of Wehrmacht survivors have passed away, who has reason to spread this idea?

(Apologies if this isn’t the best way to phrase the question, or the right place to ask it. I felt it was appropriate for this subreddit, but please let me know if it isn’t).