During my European travel, I used to ask locals why Holocaust happened? Why locals refuse to help the Jewish population at large. The answer was political situation Jewish community stayed in their tight-knit community, abuse of money/power by the Jewish community, Crusade etc.
most people stayed in their communities. Abuse of money/power? That’s what Hitler said. In your European travels, how many did you talk to that were old enough at that time to say that as their own opinion? They would have had to been born in the very early 1900s. As far as I know, the Crusades were carried out by Christians to reclaimthe land taken by Muslims.
It’s good to ask people their opinions, but make sure they’re not based on what they have been told.