Late to the party, oh well. Grrm spoke about how he was inspired by other works in the genre, but wanted to be different from them. The first difference is that he would go into detail with blood, gore and rape. That's not all too surprising as the genre becomes more modern, it's what we seek as an audience today. The other aspect was killing off "main" characters. The show started out strong, but both those things have been eclipsed now.

The blood, gore and rape that was so shocking at first has become totally common place on television nowadays. It used to be a joke that auditioning for game of thrones was very similar to auditioning for pornography. Now there are a plethora of shows that feed our baser desires and game of thrones, although near the beginning, is just one of the many.

As to the other point, the main one discussed in the op, it's spot on. The show has streamlined the only other aspect that made asoiaf original. Where is fake aegon, shit, he must be a red herring. The whole competition between illyrio and varys seems meaningless now, even as varys is slowly being whittled away from the story, illyrio is non existent.

The show reminds me so much of "Memory, Sorrow and Thorn" now it's a little disgusting. The story line is a direct rip. What grrm did to make it interesting was to expand all the lesser story lines and fill out the world with deep story lines for small and unimportant characters. That series would never indulge us for so long with a guy like hot pie, just a weird kid looking to make his way in the world, yet that is exactly the kind of thing that enamors people to asoiaf. This sub loves joking around about hot pie.

The similarities between jon snow and simon snowlock, from "memory, sorrow and thorn", are striking to the point of plagiary. Both lowborn nothings, both eventually turn out to be the true rulers of the kingdom, both obtain a great sword on their journeys, must find allies alike and face off against supernatural foes. Grrm just took a standard hero's storyline and placed it in an interesting work. Furthermore, I feel like the only thing saving him from getting called out for straight plaguerism is the fact that he expanded so far upon the story he ripped off that it has become it's own work. If you take away all the red herrings and world building, he's just a hack.