I'm glad the article doesn't try to extrapolate that HTML5 has won mobile. I doubt that developers whom attended two hackathons are unlikely to be representative of the state of mobile development.
Also, I'm unsurprised that HTML5 developers are well-represented at hackathons, IMO in the context of a hackathon, i.e. building something from scratch in a highly constrained time frame, one can achieve a lot more in HTML/CSS/JS than in a native app. This might be down to my greater experience with web technologies than native mobile development, but I believe the tooling for web technologies are better suited to rapid development, e.g. I can rapidly build layouts with tools like CSSEdit2 and see how my changes affect the document in a WebKit view, in realtime. You also don't have to run a build process to see results, feedback is in general, instantaneous.
//Also, I'm unsurprised that HTML5 developers are well-represented at hackathons,//
The pattern I observed in the internal hackathons, of the company I work for, was the dominance of web developers participating/winning over c++/Java developers.
As you said, the main reason for this was web developers were able to produce something that the audience can 'see' and in short amount of time.
Also, I've been thinking a lot about the survival of C++/Java developers in web company - because of the introduction of technologies, like Node.js. Because, now it is possible that a JavaScript programmer could do both back-end and front-end stuffs.
Well, yeah, if you're hacking a Facebook app, that implies that you have connectivity, right?
The primary reason for a native app is to provide functionality with poor or no signal. If you're doing something that's directly tied to the Internet, you may as well do it with all Internet technologies and reap the benefits (faster development, instant deployment of new versions, etc).
Also, I'm unsurprised that HTML5 developers are well-represented at hackathons, IMO in the context of a hackathon, i.e. building something from scratch in a highly constrained time frame, one can achieve a lot more in HTML/CSS/JS than in a native app. This might be down to my greater experience with web technologies than native mobile development, but I believe the tooling for web technologies are better suited to rapid development, e.g. I can rapidly build layouts with tools like CSSEdit2 and see how my changes affect the document in a WebKit view, in realtime. You also don't have to run a build process to see results, feedback is in general, instantaneous.