Lots of the Web does not do graceful degradation to fully functional sites without JS. That ship has sailed, that battle has been lost. JavaScript is a required, not optional, part of a lot of the Web.
Strongly disagree. Lots of the web may not degrade gracefully, but then also lots of it does.
Further, the notion of it as a lost battle is unfortunate because we're not discussing a binary choice between two opposing sides here. As an approach, progressive enhancement of JavaScript UIs enables developers to deliver an experience that degrades sanely in non-JS environments.
However, I will concede that your opinion appears to be the most commonly-held one, even among some developers. And it's probably not going to change for the better with news like this Firefox development... :-/
There is something to be said about the expectation when js is on and off. A lot of sites will have a notion of javascript is off == old mobile phones or low level device, and will assume that when js is off most css will be too.
Simple sites won't see this as a problem, but for mildly complex sites, you'll have a matrix of "is js on ? off ? " "is css on ? off ?" "does it accept cookies?" "is this html5 thing available ?" "is there enough memory for this or that?" , and you'll add to the mix screen sizes and the availability of a keyboard or not, etc.
There's already so many moving parts, saying "this browser handles cookies, every newest features of css, html5 and everything. Except js won't run." is just a recipe for ugly user experiences.
Slightly OT, IMO blacklisting specific js (e.g facebook, twitter etc), or having browser giving an option to kill scripts that take too much time or too many resources should be healthier for the devs and the user than just turning js off on the whole site.
