WebAssembly doesn't change this. There's nothing preventing people from doing this with javascript (plain or asm.js flavored) and canvas/webGL, and yet no one does. It just doesn't make a lot of sense.
So? My point is that most who relies on client-side code to render apps, does so in a way that integrates nicely with the browser. Most JS apps render html, they don't draw to a canvas. They could do that, but it would break a lot of functionality that people expect for a program that runs in a browser. This won't change with webasm. It will just make such pages load (and maybe perform) faster.
