"In other words, the problem now seems to be that people's perception is that firefox has remained behind and is playing a catch up game."
It was probably due at one point of time when firefox 4 was being pushed out the door. Afterwards that, they started the "be more like Chrome"-trend, while simultaneously avoiding any mention of word Chrome in public communications, and I read between the lines that they themselves thought they had fallen behind.
The rapid update process was imho a smart thing to do, but Firefox just could not work out how to shut up about it, and/or do it without breaking those extensions everybody seems to rave about. (I use none, personally.) In this, they failed to be more like Chrome, sadly. If Firefox knew how to update itself without showing the process to end users in any way whatsoever, they would reach the user experience parity with Chrome in that. Chrome has the pleasant apt-get/yum -like usage experience in that it appears capable of updating itself while still running, and shows the new version a quick restart later. There's literally nothing that interrupts users's workflow.
The reason people do not install the "enterprise" version of the firefox is that they don't even know it exists. If you go to mozilla.com/firefox/, you can only see a "Get firefox" button. (And yes, this is how it should be, also.) The normal response people have when they are unhappy with a product is that they look for competitor's product. So is it any surprise that they pick another browser? It's not like there's any shortage of alternatives. I don't use Chrome personally because it renders text incorrectly on OS X -- a bug I recently noticed when doing some text rendering tests -- while Safari renders correctly and is probably 99 % the same engine.
The reason I think some people to start getting fed up with open source development because the incessant churn in the stack that requires programs to be rewritten for no visible user- or developer-related benefit. It soured me when I was happy with KDE 3.5 and had to face the disaster that was 4.0. It was when I realized that in the past 10+ years that I have used Linux, it's been slow steps forward followed by an instantaneous giant leap backwards. And I gave up, thinking that this is how it always would be. For a brief time, I tried using Windows, but realized that the environment was simply too far away from the sort of things I needed to do---it required too much customizing to allow decent command shell and tool suite. OS X, on the other hand, is perfect.