kiyoshi
Thanks for posting that link! A very interesting read, indeed. My take on it:
The problem isn't so much the instability of the basic web development components (HTML5, CSS3, JavaScript, jQuery ...), which have all reached an acceptable degree of stability, as one of having to contend with:
1) Patchy browser support
2) Immature tools (but Construct 2 is well on the way in the gaming development niche, yay!)
3) Inexperienced developers - and here the author of the article shows that he's still got a way to go himself e.g. he complains about crossbrowser issues (his "biggest nightmare") but he apparently hasn't heard of Modernizr, which deals very effectively and transparently with these.