They should've just made the phone boot directly into the browser, and then focus all energy on making the browser better. One app. No screens, widgets, dialer, anything. Add all of that as open web APIs as users demand them. Don't bother with UI beyond proof of concept, let the web optimize it.
You sacrifice the best things about a web OS if you wrap it in a traditional OS UI.
The implication that "a web OS" is what people want raises some question marks. I use the web a lot on my phone--for reading documents. I use applications for interacting with services because, still (and this is years after FirefoxOS), the experience of using a mobile web app, especially for integrating with hardware, is awful. There may be something of a chicken-and-the-egg problem here, but at the same time--if it's awful, it's awful, and so going towards real applications is the only thing that makes sense unless you want to make devices that are awful. Nobody wants to make devices that are awful.
Letting "the web optimize" your dialer, though, is perhaps the most dangerous idea I've heard in a while. Core applications under no circumstances should be optimized by the web because that's how you get malware masquerading as those core applications. No bueno.
That's just the point. Every mobile platform that come out has tried to tell the "you don't need native apps you can build web apps story" at some point besides Android.
Instead of web apps, Google stuck the world with a sub optimal Java implementation that they spent years trying to optimize.
You sacrifice the best things about a web OS if you wrap it in a traditional OS UI.