The only reason we see it so bad to have statues of Nazis is because Germany was forced to own up to its history in a way that no other nation in the world ever did considering the Germans started one of the worst conflicts in history and committed one of the worst genocides in history thus everyone knows about it and consider it disgusting for what these statues stand for.

Other nations have statues of bad people , many Americans have statues of Confederates who fought to keep slavery, Belgium still has statues of King Leopold when he killed more than a million Congolese, China still has statues of Mao who killed tens of millions of his own people, Spain and Portugal with statues of Spanish/Portuguese Imperialists who killed and enslaved millions of Indigenous People , Mongolia with any of the Mongol Khans and of course Japan with statues of Hirohito, Tojo and other Japanese war criminals and there are many more examples across the world.

While most people know about The Holocaust many people do not know about the aforementioned atrocities or they happened so long ago that they are not within living memory which is why it's more acceptable for their statues to remain while Nazi statues are considered unacceptable in pretty much every part of the Western World.