The answer to the opening question posed by the moderator/host has a fairly easy answer coming from the point of view of those of us growing up in the US during the 50s-60s...
The educational and cultural narratives surrounding each were markedly different.
Hitler and Nazism were presented as an evil "done deal" that was stamped out by the US and its allies in the recent past. Of course the ethnic element of it, as Peterson mentions, was very prominent in that description of evil. And absent a tiny fringe of society that has always lurked in the shadows, there were simply no active proponents of Hitler and Nazism out there waving the flag. In fact, it was widely accepted that Nazism died off when the survivors of the Reich were sentenced to death or disappeared from the face of the Earth otherwise.
Contrast that to how the Russians and Soviet Union were portrayed... in popular culture we had memes (yes, we had memes back then, we just didn't call them "memes") showing the Eastern Bloc people as shrewd, but often comical foes..... Boris & Natasha.... The Russians are Coming! Ivan versus G.I. Joe.... and so forth...
And, the Soviets were still living and breathing!! They still existed.... many of us knew migrants from all over the Soviet Union.... we played with them... attended school with them.... worked with them..... and some even married them.... they were a segment of humanity that still existed....
We had a "Cold War" with them.... we competed against them in the Olympics and other major international sporting events.... recall how exciting it was to see Team Canada or Team USA beat the Red Army team or Moscow Dynamo in ice hockey.... sometimes they were portrayed as "those old drunken Russian bears...."
All of this before mentioning that in the US we have always had loud and active proponents (and sometimes hopeful allies) of the Russians, the Soviet Union, Socialism, and Communism....
Rather than view them as the ultimate EVIL that we vanquished decades ago.... these people were living, breathing 'others' that were very often just characterized as hold differing 'political' views.....
So it is quite easy to understand why those students/people have the reactions that they do.
