I don't buy that he's been sitting on an finished book, if there were any truth to that I'm sure his publisher would have sued him. What I do buy is he's made more money than he could ever spend in however many years he has left to live, so what motivation does he have to keep writing? Legacy? He's a childless man in his 70's, who has gone on record that he's not going to allow anyone to finish his books in his stead should he die before they're written. The fans? In interviews he speaks with anger about fans who ask if he's going to finish the books before he dies. The best he could do is ride out the clock with his millions of dollars and leave people wondering what might had been, rather than putting all the effort in attempting to tie up the multitudes of loose threads he's written himself into and risk disappointing everyone. It's a low bar to make something better than the show, but for years he was hyped up as "the American Tolkien", no way could he ever live up to that.