I don't see the problem with asm. It appears that Chrome and Opera support them too. It can only be a good thing.
https://blog.mozilla.org/futurereleases/2013/11/26/chrome-an...
It doesn't require requires a plugin install like NaCl
It doesn't require requires a plugin install like NaCl
That's because you didn't read the article.
Which among other things, already points to that blog post.
On a serious note, you can't really blame people for not supporting a browser that needs hack for every single version.
Related: http://www.paulirish.com/2011/browser-market-pollution-iex-i...
I am well aware of the history and I hate IE < 10 too. I use FF as main development browser, and beside others of course Chrome and IE 11. The trouble comes when people only test their website with Chrome. I am using IE 11 as I have to at my workplace and it has by far the best UX (IMHO). FF still uses only one process and cannot handle my habit of using dozens or even hundreds of tabs in an optimal way.