Many there comment that developing with HTML is faster. This is true only and only when you are not familiar with the native language and frameworks. Really, native SDKs have solved pretty much all the common problems. With native you implement the functionality of your app, and don't have to invent views management, list views, notifications, events management, gesture recognisers, etc.

There was a post (by sencha, iirc) where they brag how they managed to make html version of FB faster. I was reading and shaking my head: you get all that ingenuity out of the box with native. Two lines of code: register the class/nib for reuse and dequeue cell when needed. Hook in NSFetchedResultsController and there you have it: extremely fast and memory efficient solution. Good luck replicating capabilities of autolayout with flexbox (with rotation support). Good luck replicating capabilities of Core Animation with CSS/JS animations. How about localisation? How about accessibility? How about getting anything like Core Data?

Meanwhile in HTML5 land the debate goes on what is the best way to deliver responsive images.

Where does this notion, that mobile apps should be developed with web technology comes from? I don't see similar push for desktop apps. Is this all just because of all the web devs seeing the increasing usage of smartphones and proclaiming that html is the better way, because they are too lazy even to investigate what native really offers?

I know both stacks extremely well and the answer is very clear to me.