You have very Iphone-loving-first-world POV.(also very skewed)
As I see it B2G is a smart phone platform for very cheap third world phones. By relying on HTML5 only the phones can potentially have fairly low specs and therefore be very cheap. Theoretically the smallest platform for a smart phone is just the browser, because that is the one component you cannot leave out.
Also HTML5 "should" be the safer choice if you don't want to be sued for extortion money from patent trolls like Appl€ and M$ etc.