I won't say they didn't try their darnedest. But estimations at the very highest but the count at 10 million (this is a very generous number) and Germany had a population of 80 million at the time. 12% is scary, but still something you can overcome.

I really hope I'm not proven wrong, but something of that scale is nearly impossible to pull off in optics with the amount of recording we can do now. The equivalent in America is about 40m Americans being "deported". That's the entire Californian population and then some.

Recording makes it easier because you can get people on your side by making it look heroic and cool - for example, see Is-real. It's famously impossible to make an anti-war movie because explosions and machine guns look cool on-screen.