I agree in theory, but remember that many of these options have unintended consequences that may not be clear. So, for example, the navigation bar disappears - how do you get it back? Where did it go?
Or disabling image loading, maybe it works fine on the first few sites you visit, but then you go to the google homepage and it stops working - what do you do then? What broke that functionality? What if you're not the person who [un]checked the box?
The perspective of the post is about how regular users might easily find themselves in a situation where "basic" settings broke core functionality in the browser unintentionally, without guidance on how to fix it.
I do like the "config change history" idea, though that might be Yet Another Panel(tm) that's too complicated for the regular user. But maybe there's a "Big Red Button" that firefox could have that sets things back to a "standard" or "known good" config. These types of things are great for novice users because you can tell someone, "Look, if you get into trouble, don't know what's going on, hit the big red button".
I've used stuff like this for certain family members who are not great with cmoputers - rather than trying to teach them all of the different knobs to twiddle, spend a lot of time teaching them how to get to a known good state ("Close all fo the windows and restart", etc.).