I mean, I know you will assume you're right, yada yada yada:

http://developers.slashdot.org/story/12/09/12/0336205/zuckerberg-betting-on-html5-was-facebooks-biggest-mistake

 "'The biggest mistake we made as a company was betting too much on HTML5 as opposed to native. It just wasn't ready.' According to Mashable, 'the benefits of cross-platform development weren't enough to outweigh the downsides of HTML5, which pulls in data much more slowly than native code, and is much less stable. ... Now, Zuckerberg says, Facebook is focused on continuing to improve the native mobile experience on iOS, as well as bringing a native app to Android.'" 

http://mashable.com/2012/09/11/html5-biggest-mistake/

So basically, he reckons apps are far better for mobile devices.

Hmm. Interesting...