This weekend I had a chance to play with a Jolla smartphone. Hardware wise it pretty good, and had some really good ideas, but the software was half baked. While in time both Jolla and Firefox OS could become great products, but time ran out a while back.
You now have to come to market with all the pieces (and then some). You can't adopt the "build it and they will come mantra" because unless you can give users a compelling reason to switch without losing functionality they won't come. The hardware wars are long gone. The app wars ended a few years back. We are now in the ecosystem wars and Mozilla (and Jolla) appear to have no answers for this (or have answers "coming soon").
The sad fact is that from here on out it's iOS and Android in a tussle neither can win, and unless the phone market resets itself like it did in 2007 there is very little anybody else can do.