If there is a badly implemented datepicker written in JavaScript you can use a different library. A good JavaScript library will make sure it works with consistency and as expected in different browsers.
My phone has one phone-optimised date picker; my PC has one PC-optimised date picker; my screen-reader has one screen-reader-optimised date picker. Sure there might be other versions for other platforms, but I as a user would only interact with three, and those three are all consistent and optimal for their situation.
Seems much better than our current variety of scripts which all target the desktop PC and fail at it, and don't even attempt to work on any other platform...
> If there is a badly implemented datepicker written in JavaScript you can use a different library.
Not if it's on somebody else's site I can't.
> A good JavaScript library will make sure it works with consistency and as expected in different browsers.
A library written and deployed today will work flawlessly with the browsers of tomorrow, including things like screen readers which the library author hasn't even thought about?
Taking your logic further, why bother having HTML parsing, layout, or rendering in the browser? In fact, if you object to the idea of semantic markup and would rather manually specify every detail of every element for every situation, why are you using HTML and not giving users a .exe? :P
I personally dislike that CSS is turning into a miniature programming language, but I assume this is the way forward until something way better comes along and simply replaces HTML, CSS, JS. I mean its better to say width - 10 pixel than to make JS for each silly snipet like that.
The more web projects I work on, the more I like desktop technologies.
Thankfully many are doing native on the mobiles, and the stories of companies being burned by HTML5 not being ready help as well.
So your suggestion on how to make the web better is to abandon it. Okay, your input here is done.