Very interesting, but most of these examples look like they would be fairly nonsensical to someone without JavaScript enabled (especially the line chart). To say nothing of those who use screen readers. Is there a handy way of providing some more meaningful 'alt' text? Perhaps just ignore text in the element? (I didn't check -- you may already be doing this, but I didn't see it mentioned).
Who isn't using javascript?
People who keep it disabled on all but a few white-listed sites.