The problem really comes down to this: is Nazism something which we are all capable of quickly becoming, i.e. inherent to human nature, or do we only become this horrible when small groups of intelligent elites cynically exploit our psychology and concretely plan for us to become brainwashed slaves (the opposite of banality)? Perhaps a bit of both, but at some point someone definitely isn't a banal and clueless bureaucrat.
You can probably see how option A is a propaganda win for Nazism (and fascism in general). 'See, you're not so different to us!'. Was it the German people who became Nazis overnight, or did the Nazi elites (such as Eichmann) instigate what amounted to major social engineering campaigns?
The point is that in most cases you don't need any major social-engineering. The elements of efficiency and obedience to the hierarchy are already there, built-in in most orderly societies. You just need to veer the actual aims a little bit, and you are effectively in a regime not very different from the nazi one.
That's why seemingly democratic societies can turn into regimes almost overnight.
This is discounting all the times people fight back against fascism though. Lots and lots of people absolutely do not accept some natural link between orderly conduct and fascism, and so that goes back to my original point about Eichmann making Nazism seem banal as a goal for the Nazi ideology - if we're basically one step away from becoming Nazis at any point, is what they did really so bad?
Well, yes it was, because it was engineered. The Nazis never won a majority in any election, but once they were in power they were famous for their social engineering and propaganda. They're a classic example of how a minority of people in a population can absolutely gain control over everyone else and bend the majority to their will using highly cynical but intelligent tactics.
> This is discounting all the times people fight back against fascism though.
That's a personal interpretation. In fact, in many ways it doesn't discount it but actually inspires them, asserting that without such efforts society is likely to backslide into fascism fairly easily. Which tbh, if you've lived in the US from 2001 to 2005, or today in Russia or Hungary, you've basically experienced already.
I think it's correct to say that a lot of people are relatively passive and will eventually go along with whatever a government desires, but the crux of the 'banality of evil' argument was that Nazis at the highest level were also that kind of passive, bureaucratic evil, as opposed to being very explicit and knowledgeable in their plans. The critique of Arendt wasn't that there was no banality of evil, just that it didn't exist at the levels she claimed (Nazi leadership). They knew full well what they were doing. It's important to recognise this since otherwise you might say that the people in power aren't important as they're purely products of societal values etc.
Like in all things, it's important not to end up on the maximalist end of the spectrum. Obviously an individual is not only the result of a certain social conditioning nor only an isolated madman, and that's not Arendt theory; but it's undisputable how even the leaders brought to extreme consequences certain societal instincts that were present. When you compare the qualities of Italian fascist leaders with German ones, for example, you can see the differences: while Italians were focused on heroism and individual excellence (as expoused by D'Annunzio, for example), Germans valued more order in all systems - which is why the holocaust was as effective as it was. That's because the societal views that shaped them were different.
That does not mean that society carries all responsibility for the actions of this or that person, of course, that's never the case. What the banality of evil tells us is that society contains the conceptual germs for behaviour that can turn atrocious, when brought to extreme lengths by this or that individual.
You can probably see how option A is a propaganda win for Nazism (and fascism in general). 'See, you're not so different to us!'. Was it the German people who became Nazis overnight, or did the Nazi elites (such as Eichmann) instigate what amounted to major social engineering campaigns?