Facebook and YouTube, as highly interactive applications, are not "most websites".
Practically ever single blog, news site, store, business page, and the like have zero need for Javascript, and requiring it only makes your site look broken. The maybe better with Javascript, of course.
While I haven't worked on websites in the last year or so, I have made websites professionally in the past for many years. Making a progressively enhanced store that works without Javascript in Rails 2/3 was really easy.
> vast majority of your users will never even consider turning it off.
How do you know this? Are you guessing? Are you relying on Javascript-based analytics and are therefore blind to people that disable Javascript? Do you have server logs that show how many people disable Javascript? Is you site broken without Javascript so this claim becomes a self-fulfilling prophecy?
I ask this every time someone makes that claim, and have never gotten a response.