The web is a great distribution platform for one subset of applications (news, email, social, etc.) and a bad distribution platform for basically all others. Pixlr is a great example; GIMP will do everything Pixlr does, faster, and without a network connection (yeah load time is bad, but that's a GIMP-specific problem). GIMP doesn't have to pay any money, other than hosting (which an asm.js application also would have to pay) to distribute their app. I can use GIMP without downloading it every time. I can also continue to use GIMP if/when its developers decide to give up. When Pixlr's developers give up, it's gone for good.

I also think pouring millions of man hours into a transpiler and JavaScript engine optimizations is probably the least efficient and most convoluted way to take advantage of the web as a distribution platform. I think the way this should all be framed is, "it would be better if browsers supported a lower-level bytecode, or more languages, or both, but that's politically impossible to achieve, so we have asm.js". That's the only thing that makes sense to me here.