They're already written? They come with built-in fanbases?

There's a new article at the Verge called "Why Hollywood is turning to books for its biggest productions". While the author makes a couple of decent points in the second half of the article, he confuses me early on with the suggestion that faithful, ambitious TV/movie adaptations of books only began with Peter Jackson's Lord of the Rings series in 2001. Everything from A&E's Pride and Prejudice to freaking Carrie says otherwise, dude.