I'm curious why? I built a JS-driven website and did extensive testing with the screen readers available to me (phone, etc). Adding a few aria properties seemed to work wonders. I think the problem isn't the SPA concept but rather that people don't bother testing. However, a horrible screen reader experience can be achieved without an SPA too and many do.

JavaScript driven SPA is fine as long as everyone remembers that the entire and only point at the end of the day is to create HTML.