I guess with Nazis, there is a chance that a revolt eventually happens and ends their reign. It’s less clear how humans come back from being paperclipped, so maybe that’s his rationale. But it’s a foolish question because of the antisemitism that looms in any discussion of nazis.
I prefer this variant of the question:
Would you rather all of humanity suffer in eternal Hell, or cease to exist?
That’s a pretty clear one for me.