Its not just that - but everything about FF seems to be going the wrong direction... I have a heavy ajax site that uses jquery - it works great in safari and chrome. IE is a little slow at times, but we all know that. But firefox just locks up after less than an hour... yay! Reported it - sits there for weeks now without being assigned or anything else useful happening.
They want to stop supporting http - what an idiotic thing to even talk about. There is lots of valid use for http, including developing something real quick without bothering to get/create an ssl cert for your internal box, setting it up and all that. Older websites and apps. Things where you just transfer bulk data that is of little value.
Or the fact that they deprecate apis without replacement. I have a firefox plugin that shows up as a page action in the URL bar... the api to attach a popup is depricated since about 2 years... But - and even the devs admit that - without a replacement that works the same way or similar. No, you now have to move the popup and overlay that little indicator showing that the popup is attached to the icon yourself. Really?
Anyway - I hate the Chrome UI, so I use the Classic Theme restorer. It has a good rating and an install base of 450K ... if that doesn't say it all I don't know what does.