I think it used to be a book shown on television, now it's just a television show.
It used to be a book that avoided the trappings of typical "hollywood" tv/movies and that was why the show was so interesting and fresh. Then it flipped and is now firmly in the tv show category and is doing tv show things and falling into fairly standard tv show formulas and tropes (or variations thereof). For many it's really popular for b/c of that; they LIKE those formulae.
And I think I can pinpoint about when this flip happened. It was season finale of season 5 when Theon and Sansa jumped off the wall of Winterfell and the camera cut away. It was the previous season when the Hound was left to die and the camera cut away (in an a fantastic moment w/him and Arya). It was when Stannis was executed after the battle and the camera cut away. These cliffhanger-esque moments didn't happen before and they feel like TV teases and even at the time, it felt like "really? You're resorting to THIS?"
Next season, we catch up to Sansa and Theon running in a forest being chased. Oh I guess they landed in a snow bank or something? (not that we really thought they'd die or whatever). Later, we see the Hound is ok and chilling with some Habitats for Humanities dudes; this totally undoes how awesome that moment was with Arya/Hound (imho). This is like a move that a show makes b/c a character is too popular and just feels like it violates the core of Game of Thrones. So then, it feels like all bets are off if you don't see a character die. Ok, so can Stannis come back ? Probably not b/c he wasn't popular, but if D&D wanted to, they could do it. How about Syrio Florel?
And as nice as it was for Jon Snow to come back? It felt too easy for me, like the writers just gave themselves a just too easy out so that they could have a "subversive" season finale. I know GRRM had Lady Stoneheart and so even in the books the dead don't nec stay dead, but she didn't come back fine; there were some serious ramifications.
And I totally hated the whole High Pigeon thing. It was an entire plotline that totally did not matter at all b/c they nuke the lot of them at the end. It's the equivalent of an "It was all a dream"; the writers could do just whatever crazy thing and then bang, it's all over at the end with no real impact. ugh.
And Arya's entire storyline in the House of Black N White was so terrible mostly b/c it was so truncated. My personal opinion at the time (though I know it was impossible) was that they should have excised Arya's story from Game of Thrones and made a 6-8 ep spin-off series of Arya at the House of Black N White that played between season 6 and 7. That would have been able to delve deeper into all of Arya's training and the entire mythos of the Faceless Men.
and i'll say that even in S5, these little writing issues were starting to show. And I personally am not really that MAD at the writers. I think they are doing the best they can and what they think is the best for the show. I just think they are just not imaginative, inventive, insightful, clever, and versed enough to really work the story like it needs to be. And compounding that is the time limitation and the restriction of preparing to write the show. I mean, GRRM himself can't finish the books (although in my alt universe fantasy, GRRM has written the rest of the books and is holding them back to release in total right after the series finale) with all this extra lead time, so how could these two tv guys manage to create them ?
Sorry for the wall o' text. Just got off on a bit of a rant