For the most part, I have an external password manager where I keep my passwords, or simply remember them in my head. I don't find the browser to be a good security boundary for keeping things I actually care to protect, and I have no interest in using "Firefox Sync" or whatever else to drag my browser sessions along everywhere, so it's more inconvenient in general. For some sites, though, it doesn't matter as much, and I don't mind storing my passwords in the browser for those, the convenience is worth the extra risk. So that's what I do, most sites I never want to remember the password on, but on some of them I do.
Imagine my shock then, when I finally went to turn off the setting to "Ask to remember passwords", and suddenly found that my passwords are no longer being autofilled. As far as I can tell from searching online, it appears that the setting does not, in fact, only toggle whether you will be "asked to remember passwords", but also whether the password will be autofilled in the first place. The passwords are still stored in the browser, but they are no longer being autofilled.
These are two separate concerns! I want autofill on the select few sites I choose to accept the extra risk on, but by default you can assume I don't. If I want a new password to be remembered, I'll add it manually, no biggie. But I really wish there were two separate settings for these cases. While I can't really imagine a case for wanting to be asked if the browser should remember the passwords, but not wanting it to autofill, the other way around I think is certainly reasonable. It's a feature I want to use on a select few sites sometimes, but the box popping up on every other site is annoying. I want to be able to use this feature without my browser nagging me about it.