Curios to why RR2 still haven't been made? Then this might interest you.
The Dissolve has posted an article with theroies on why RR2 hasn't been made yet.
And also gives us reasons on both why it should and should not me made.
And if that wasn't enough, the same site also has a series called "Movie of the week" where they discuss classic films. And they've done one on Who Framed Roger Rabbit. Where they share with us their opinions and observations on the film.
And if you are STILL not satisfied, they have also written a article about Richard Williams and his pet project; The Thief And The Cobbler.