I think one basic problem with Firefox OS being a "developer-first" thing is the devices it's being shipped on. Of course, a $33 phone is a very cool thing to be able to do. But as a developer, a lot of my disposable income is going to be directed towards gadgets and a $33 phone is just a decade behind the types of phones I would actually use myself. I think that to attract developers, Mozilla should aim to find a pa…
A significant proportion of the weight behind non-web based UI comes from the need to efficiently leverage the GPU. You can almost get away without this on low res screens, but at 720p and beyond you need it as the sheer number of pixels starts to kill you.
Google have thrown massive amounts of effort into making Chrome look like it's almost there, but the reality is the layout model doesn't map to well performing GPU primitives nearly as well as, say, Cocoa. Mozilla haven't been able to get even a fraction of a distance down this path.
For this reason they'd have been better off chasing something like e-readers, since there the update speed isn't a big deal. But don't let anything like reason, logic or technical competence get in the way of Mozilla's decision making.