I think there were lots of good reasons to have more layers of abstraction between apps and OSes - portability, security, ease of deployment to name the obvious

I think there were lots of good reasons to have more layers of abstraction between apps and OSes - portability, security, ease of deployment to name the obvious ones. Browsers were the wrong thing to target but they were the only thing getting even vaguely standardised across the proliferation of devices and OSes. The problem I think was the pace. Nobody really had a chance to say "hang on folks, if we're going to do lots of this we need to talk about javascript and the DOM". Now we're stuck with it for good. At this point the best we can hope for is to put a better layer on top and treat it as machine code.