Mistakes happen, it's okay. But users should be empowered to work around them.
The issue is that if you leave any sort of lever that reduces security, it will be abused by bad actors. This is why browsers are having ever decreasing ways to bypass security and have full access. It is annoying, but at the end of the day, protecting 99.999% of the users trumps what us power users want.
It is horribly paternalistic to advocate for keeping users ignorant, unlearning, and --- dare I say it --- easily manipulated.
I will refrain from mentioning again that infamous Franklin quote. I am frankly very fucking pissed off by this authoritarian walled-garden trend, and vehemently oppose anyone who helps this industry put the nooses around the necks of others as well as their own.
I still don’t want to have to understand everything I ever touch, even if I could.
If you don't understand it, don't touch it. The default settings should work for most users. There can even be a warning against touching without understanding, like with Firefox's about:config. The offensive thing is preventing users from touching even if they do understand.
I'm not disagreeing with you, but the right mechanism is not straightforward to figure out, and you'll always be in a game of cat and mouse. One that sucks resources from whatever other useful stuff you might be spending your (or Mozilla's) time on.