I remember the good old days of Firefox 1.5 when there were more extensions than you could shake a stick at. You actually had a choice of which extension handled tab functionality best.
Then Firefox got updated and 1/3 of all my extensions got trashed. So I spent a week searching for equivalent extensions that almost worked the way I wanted, but never quite exactly the right way.
Then it got updated again and another 30% went. Another week spent searching for equivalents.
Then they moved to "fast release" cycles and the extension writers said, basically, "We've had enough of re-writing our extensions every time Mozilla changes the way Firefox works."
That's the polite version. I know what I thought. So I didn't update it. I'm still running Firefox 28 on my XP machine. All of it's 92 extensions are working fine. I only use Opera or Chrome when web sites don't work properly. But neither Opera nor Chrome can do what my Firefox 28 and its 92 extensions can do.
So that's what happens when you rely on the good will of extension creators to improve your product and then p*** them off by making them rewrite their code, over and over and over again.