The GRRM criticism reminds me of a peeve I have with him. It was back years ago, but I remember he said something about how LOTR is unrealistic because of the moral clarity, how there are explicit good and evil characters, but in real life there is complexity and "shades of gray".
Yeah, it's trite, but that's not what got me. It's that I've read some of the ASOIAF books, and they really don't have "shades of gray". The Starks are mostly good, the Lannisters are mostly evil. Davos Seaworth is good, Ramsay Bolton is evil. It's the same moral simplicity, just in a sneeringly cynical world.
That said, I will give credit to GRRM for his creativity. The world of ASOIAF really is very interesting and fun, despite its cynicism. And because of it we have the
Alt Shif X channel, which I honestly find far more entertaining than the show. Or even the books, for that matter.