I'm not sure why this was downvoted. While his remark about lawyering up may be overkill (unless you work for a federal agency and have to abide by Section 508 rules), his point about excluding those who rely on screen readers is dead on.
I've found that one of the major complaints that blind users have is that it's a total bitch to work with dynamically updating pages. If more developers paid attention to web accessibility, a lot of the major problems to disabled folks would be greatly alleviated.