Earlier quoted context omitted.
Unfortunately, I think you're right. Mozilla has been fighting a slow war on all powerful UI customization. See: the recent killing of Tridactyl.
Reports of our death have been greatly exaggerated :) You can still install Tridactyl in a normal installation of Firefox by following the instructions on our readme [1]. Admittedly, that may cease to be the case if Mozilla ever tire of us; people in locked-down corporate environments would then find it hard or impossible to install Tridactyl but we'd make it as easy as possible for everyone else. On topic, I'd argue…
> On topic, I'd argue that Mozilla are just desperately trying to cling on to ordinary users; the "war" against power users is a war of (totally understandable) neglect rather than spite.
Perhaps, but meanwhile, as we muse about Tridactyl and the abandonment of userChrome and userContent, a thread about the possibility of Firefox removing webRequest in the future rises to #2. It's getting harder to justify Firefox and Mozilla by the moment.