Let’s talk about the Macedonian colonization of Asia. Or Egypt’s colonization of Africa. Or Rome’s colonization of Western Europe. Or Khan’s conquests of Eastern Europe. Or Atilla’s ... or Saladin’s ... or the Lakota conquest of the Black Hills ... or the tribal conquests of the Aztecs, the Incas, the Mayans ... Then there’s Shaka Zulu ...
Why single out the Germans? Mao and his ideological brethren slaughtered a lot more than Hitler ever did. And that was in recent memory.
Hitler got the idea for Concentration Camps from what the British did to the Boers.