Your comment is an example of a false dichotomy. We do not have precisely two options:

A) He's right and forcing them to allow frameworks will slow computing as a whole B) He's wrong and cool apps will start to appear on all the competing platforms

There's also, just as one example:

C) He's wrong but large numbers of cool apps will not start to appear only on competing platforms (perhaps because the app markets on all those platforms combined are dwarfed by Apple's App Store)