[plgviyzk] Movies based on CC-SA books

To my knowledge, we have yet to have a major motion picture based on a book licensed Creative Commons Sharealike (which forces the movie itself to become Creative Commons).

Does publishing a book CC-SA make producers avoid it (poison pill)?  Or is the lack of such movie adaptations simply the result that SA, especially without the NC restriction, is still fairly rare?

Of course, we have had many movies based on public domain works, and movies are club goods at the theater.