Earlier quoted context omitted.
Not a Google engineer, but I can offer a partial explanation. As you probably know, up until the release of IE9, supporting apps across the major browsers (Safari/Chrome, Firefox, IE) was a massive PITA. Not just obscure features, either; even IE8 had some crippling misunderstandings of the CSS 2.0 standard (floats). Today desktop cross-browser problems are consistent subpixel antialiasing and less-critical CSS featu…
AFAIK, IE10 on mobile has the same JS engine as the desktop one. What data you have to say that it is slow? This benchmark says its the fastest: http://crockford.com/javascript/performance.html Besides how do you explain the uk site that was working already that then got blocked?
(Exactly. It's probably political as I mentioned before.)