Someone among the Germans (a Jewish German especially) actually TRIED to shoot Hitler. That didn’t work and if anything made the Jewish persecution even worse. Heck, a group of German military officials even attempted to outright bomb Hitler in his own private estate (Operation Valkyrie), THAT didn’t work. So yeah, while it would have been nice if someone did do that, that wasn’t even close to a feasible plan at all. Hitler’s the paranoid type, often changing plans just to upset any potential assassinations against him.