Obama called Auschwitz a Polish Death Camp. It was about as Polish as the 9/11 attacks were “American” Atrocities. Both crimes took place somewhere, but the perpetrators were from elsewhere.
This entire snub almost certainly arose from the same reason Obama so often gets various historical facts wrong: he, and others like him, are in love with themselves and having the right sorts of opinions, but they’re all deeply immersed in the kultursmog, are not necessarily that curious intellectually. In addition, the elite schools they attended do a worse and worse job of inculturating them in the basic historical facts of the last few thousand years. They run around with thoughts like “the Americans gave Indians blankets infected with smallpox” and “the US had these terrible racist ‘concentration camps’ for Japanese” without ever looking beyond the headlines, so to speak.
Indeed, various fields including “structural realist” international relations and the like are all about skipping over the difficult and murky work of real historical understanding and coming up with various shortcut formulae to understand the world, but as a result we end up with stupid-sounding and overconfident people like Obama and his speechwriters. And they end up creating real practical problems in both domestic and foreign relations because they do not understand real human beings very well.