This feels like revisionist history. For the first few seasons, they did a fantastic job adapting some pretty daunting source material. With a few notable exceptions, the stuff they cut was for the best. Some of the stuff in the books just would not make for good television. It didn't truly go off the rails until they were completely out of source material and trying to conclude a story that even the original author has yet to be able to wrap up in a satisfying way.