Edit: Graceful degradation should be a tenet of web development. Having no provision for a person who doesn't have javascript enabled seems bizarre to me, and being bullish about the requirement seems even more bizarre...maybe i'm just getting cranky with age or something.
It is one thing if we were talking about a webpage ala 1995 for joes autoshop. At most it will have a comment field (or, the horror, a guestbook) and each url will map logically to a specific public part of the site. Most likely there will be no concept of users at all.
The same thing goes for a blog although you won't get the auto updating twitter feed and, if the blog uses diques, you may have to click a couple of links to see them.
But a webapp is more like Google writer. It just lose all meaning to make it work without Javascript.