I've worked with both and I can say this is just a case of "the grass is greener".

Nothing "exciting" about HTML5 and the Web for people well versed in a mobile framework. The most interesting things are re-inventions of the wheel, only more hacky and less performant.

Plus, since you can use web views in your native mobile app, there's literary nothing (technologically-wise) you can achieve with HTML5 that you cannot achieve with a native framework. The inverse is not true. Anything that requires extensive collaboration with the underlying machine, low latency, ad-hoc connections to interfaces etc is not possible (you cannot write Garageband with HTML for example. And Flipboard or even Clear would have been noticeably slower).

(Except the distribution method of course -- but then again, nowadays people still debate if it's all about native or it's all about the web, so that's like 50-50.)