There are a lot of those little frameworks that try and bridge all this together: PhoneGap, Titanium, etc. They're all varying levels of terrible (unless you want to make games, in which case Unity mobile is a pretty solid bet).

So there is a market, people are trying to fill those gaps, and yet none of them seem to be able to bridge the gap in such a way that devs prefer maintaining two or more native apps over one that compiles for multiple devices with a common framework.

So there is a market, but it doesn't look like it's an easy problem to solve.