No one has ever given me a good answer on this. Why can't we just make screen readers that render Javascript? At least execute any javascript that runs on page load, and then read that modified DOM.
You could probably just hack the Firefox code to do it, no big project necessary.
Really, though, the problem is one of established vendors with a lock on the market and, consequently, little motivation to improve their products. Sound familiar? At first pass, this would seem like prime breeding ground for startups, but there are serious barriers to entry.
The biggest obstacle for new products is just that visually impaired users are taught to use JAWS from the get-go: they have the educational market. Yes, they hate it, but when you can't see it's very hard to comparison shop. All screen readers have a big learning curve.
Then, if someone could find your product, evaluate it, and like it, well... most people in the target market are not self-sufficient, and would not actually be able to pay for it. (You would have to market to the charities and grant foundations that purchase the products for most users.)
Oh, and did I mention that it's not easy to write a screen reader in the first place?
As much as I would love to see a startup come into the arena here and change the rules, I think instead we just have to hope for the success of these various open-source projects, and be glad that there are people who take this problem very seriously and are working on it.
Until then, designers and programmers will have to cater to the various quirks of the market leaders. This article is one of the best guidelines for that I've seen.
You could probably just hack the Firefox code to do it, no big project necessary.