Yes, and what we'd also need is software to support such activities. I was recently thinking of implemeting a cms-database for that, offering people the chance to describe my images in more detail. I did supply alt-tags, but maybe in some cases an additional long desc would be helpful. I think to programm such a tool would not be that difficult, but I wouldn't find the time to describe the images myself. I thought of additionally presenting images with an href-link to an input-form where such descriptions might be written. If the writer is offered the opportunity to set a backlink to his own site, this might be a lot more interesting than blogspamming.
I wonder whether webmasterworld is really the place to dicuss/complain the MORAL aspects of these lawsuits. In the first place I see a MARKET there, a technical challenge. Maybe google will one day implemet a '<doublerel>'-tag for such VI-long-desc-blog-entries, inheriting double pagerank to the site that was so friendly to help the blind.