is she acting "normal" these days? Last I had heard, she was showing up really late for her own shows. If you're the producer of a movie, you might not want to pick her if you're gonna have to deal with someone who might cause your shoots to run late, etc. Not to say that she wouldn't have been a good choice minus all that shit, but she may not have been worth the potential headaches.
Fuck it though... they could have gone for Viola Davis and as far as the acting part goes, she'd do as well as anyone, and close enough looks-wise... not sure if she can carry a tune though