You know what really bugs me about Firefox?
8 years (I think?) of copying superficial elements from Chrome, but they still haven't caught on to the single most significant improvement Chrome made: putting every tab in its own process!
How long will it take for Firefox to finally knock-off the one truly useful thing from Chrome instead of wasting time copying its UI stupidities?
I was under the impression that this feature was a bit controversial (and as such, might end up as another misfeature ripped off Chrome). Answers to your post did nothing to dispel this impression.