As I was reading this article: http://www.netmagazine.com/opinions/too-much-javascript this thread cropped up in mind. Interesting read.

It also affirms the explanation that you posted above on why JS rich websites are not friendly for visually impaired people.
Text-to-speech interpreters and magnification tools can operate incorrectly or, in some cases, crash an entire page when encountering some hastily inserted JavaScript. Or, if the site is wholly reliant on JavaScript, then it doesn’t work at all.