I think Final Fantasy is just being scapegoated as a reason to not do photorealism.  Look at The Polar Express and Beowulf - which had decent stories and were photorealistic.  So it is possible to have a successful photorealistic 3d movie.  I think it's more of an issue of marketing - if movie makers make films more cartoony (which Pixar admittedly does), then they able to attract a younger audience.

On a side note, in terms of bad actresses, Katie Holmes hasn't done anything since The Ice Storm that has been worth watching.