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 do think that in the future, it will be imperative for everyone to have some level of technological literacy above what is currently the average. And I'd like to work to get to that point, instead of taking all the tools away because they're too dangerous.
Also, sensible defaults are good! Hiding dangerous settings is also good! What's not okay is making those settings completely unavailable. At least in Firefox's case you have the option to recompile the source code, but that should not be the only recourse...
If we're going to be authoritarian I would rather ban anyone who doesn't understand that from connecting to the internet then have a broken walled garden.
If we're going to assume that software is right and the user is wrong 100% of the time, then the software needs to actually be right 100% of the time. Unfortunately, our software isn't that robust, and it never will be.
That is absolutely complicated for the vast majority of the world's internet users. No one else is my family would understand what the hell "privileged code" means and shouldn't have to.
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.
Adjust the qualifier at the end depending on your platform. On Windows, it might be apps that present a UAC dialogue—or maybe just remove the qualifier, since Windows doesn't do much sandboxing by default.
If you want your freedom from reviewed extensions: fine, get an unbranded Firefox, or Developer edition, and you get that.
In this case, dropping the extra control/ignoring power users is probably saving a lot of non-power users from shooting themselves in the foot in the vast majority of cases. Pilots (should be) 100% power users. The average operator of a browser is somewhere on the opposite end of the spectrum.
Any real system will have things go horribly wrong for some subset of users on a regular basis. It's impossible to be all things for all people for all situations, so you have to choose your battles.
As you can see in this discussion, there already are some obtuse ways to disable/ignore the signing. It's just way worse if people have to disable the signing instead of adding a trust for their own certificate, so that only mozilla and user's addons are truste instead of all the malicious garbage out there on the web.
If you can recommend an fork that allows extension sideloading but is kept up to date, please do so, I’ve been looking...
Unbranded Firefox is actually a specific version of Firefox distributed by Mozilla, which allows you to disable extension signing requirements. I am very glad to see that they offer this, and I will be using it from now on.
https://wiki.mozilla.org/Add-ons/Extension_Signing#Unbranded...
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.