Well to be fair the book.... OK the book was a nice read. I hated Clash of Kings the most but obviously this was a pretty big drop off after Storm of Swords.
But as I was reading the book (or books), it never felt like it would successfully translate onto screen. It's just not movie material at this point, all the intricacies, all the little things they left out in the past added up.
On a lighter note, I like that (based on the build-up), most seasons end with Stannis being involved in a battle haha. All over the continent.