Those metrics tell us everything we need to know about Mozilla's efforts these past few years: people in general are not happy with them, to the post of abandoning Firefox.
As of recently, that trend has finally stopped: Firefox has started gaining (very) small amounts of market share recently. The point where the speed of user attrition slowed down was actually slightly before the Australis launch, but after that, the development sped up considerably.
Thus, it looks like Australis helped substantially with winning back users.
Plus, a few years ago, the competition was essentially IE6/7. Not hard to gain market share against that. Now there are several great browsers to choose from. Which I'd say is a fantastic development, even though I work for Mozilla.
Finally, there are the billions of dollars that e.g. Google pours into advertising for Chrome, which might have something to do how market share developed.
[citation needed]. remember that people bitching on web forums does not equal the general population's impression. firefox has extensive telemetry in the browser -- i'm certain that if australis hurt usage metrics, there'd be changes, or at least discussion in the mozilla community (which, of course, is essentially all publicly visible)