Tweeted to Chris Beard: "Dear @cbeard, please give your users the choice and control they deserve in @firefox. Allow extension signing to be disabled in FF42."
You want to protect the user, then start making extensions more secure and require permissions to do things. E.g. If an extension can access contents of webpages, pop up a dialog and ask the first time. There are other ways to protect users without going authoritarian on us.