> No, drop down menus, pre-validation of forms, adaptive rendering are the daily experience. Javascript is just the way we currently achieve that. I argue that a better html would avoid having to do this in javascript, as these are standard features that are needed everywhere.

You can certainly standardize a certain set of feature and put them in a non-turing-complete language like HTML, but standardizing all the legitimate use-cases of JavaScript is almost impossible, you talked about «drop-down menus, form validation or adaptive rendering», but what about interactive charting, modal view of full-size pictures, auto-completion of search tags ? These are just features I use on my personal blog ! And what about infinite-scrolling ? What about partial content-update ? There are thousands of legitimate use-case for JavaScript: it's not achievable to standardize every single one of them and put it in the HTML, and even if it were possible, do you imagine the nightmare it would be to learn HTML then ?

> but standardizing all the legitimate use-cases of JavaScript is almost impossible

I see the problem of not always having the newest technologies in browsers, but the pain of that problem vanishes the more we already have. One might say that securing JavaScript sandboxes is almost impossible, but still we are working on it. Let's work in the same spirit on advancing the open web :-)

> non-turing-complete language like HTML

I would be careful about that: It wouldn't suprise me if HTML with CSS (at least with all the new things like animations) is turing complete (it probably is).

‘You can encode Rule 110 in CSS3, so it's Turing-complete so long as you consider an appropriate accompanying HTML file and user interactions to be part of the “execution” of CSS.’

https://stackoverflow.com/a/5239256/453783

If history is any indication, getting browsers to design, agree upon, and implement "better html" would take about as long as fixing cpus.