Not every TL will have a situation that allows for a Hitler-analog to rise, do the damage he did, and become the slain-dragon foiundation myth of the two military superpowers that dominated the world after him. It's pretty unique (and you will note that while Hitler is nowhere an unemotional topic, he's certainly less charged and absolute in parts of the world where the ecvil bastards were the Japanese (or the Allies as colonial overlords). It's not enough to just kill millions of people to be an alt-hitler.
that said, every TL is liable to have some epic villain whjose name is invoked in discussions of political crime or atrocities. Mind, these often tend to be geographically limited example. The charge of being "a second Gessler" or "red-handed as Huangdi" may mean as little to the aerage American as that of being a "Benedict Arnold" would to a Swiss or Chinese. Some re likely to be common among the educated classes (as long as a remotely European analogue culture exists, likely Nero, Caligula, Commodus, Attila and Genghis Khan). But they won't be as central.
So, Godwin is owed to a fairly unlikely historical constellation.