This is horrifying on a number of levels. I don't think that even Google has tried exerting this much control over users.

This does not make sense if it is just to fight malware. I no longer believe that Mozilla is acting in good faith. It seems that Mozilla is trying to claw control of Firefox away from users.

I do not trust them to decide what extensions I can have. Once they have locked it down even more, are they still going to be so nice about approving extensions?

Either this is just hubris and contempt for users, or a poor attempt to copy Google's restrictions, or something worse.