Game of Thrones star Isaac Hempstead Wright says George R. R. Martin chose the fate of his character Bran Stark as revealed in the show's series finale. If you are - or were - a fan of the show, you're certainly aware of the controversy surrounding how the series ended. The final episode earned the show its lowest-rated episode on Rotten Tomatoes, with an abundance of criticism over its creative direction. Among the the complaints was the revelation Bran would be named king, as many viewers were underwhelmed to see him as the one to take the Iron Throne after providing no assistance with the battles at Winterfell and King's Landing. However, spare showrunners David Benioff and Dan Weiss from those complaints, as Wright claims this was a call made directly by the author of the novels, George R. R. Martin.
"David and Dan told me there were two things George R.R. Martin had planned for Bran, and that was the Hodor revelation, and that he would be king. So that's pretty special to be directly involved in something that is part of George's vision. It was a really nice way to wrap it up."
It's interesting Wright also cites what happened with Hodor as a creative decision to come from Martin. In the episode "The Door," Hodor sacrifices himself to keep Bran save from incoming White Walkers. It is also revealed how Hodor came to acquire his name, which was the result of Bran's time-traveling to the past. The episode is critically acclaimed and was met with positive reception upon its release, so it may be unfair to say the King Bran revelation came as the result of "bad writing." Still, the argument can be made that it wasn't the best direction to go for the show's final episode, but that is of course subjective and is being widely debated upon by fans.
Following the end of Game of Thrones, Martin promised that he would soon release the next books in the series that inspired the HBO show. He commented that the books would have some differences from what we saw happen on the TV series, although there would still be some similarities. If Martin was the one who told Benioff and Weiss to put Bran Stark as ruler of the 6 kingdoms, this could be because it's what he has intended to do all along in the Song of Fire and Ice novel series. However, it could also be because Martin is going in another direction in the book and wants to surprise readers when they get to that pivotal moment.
Aside from what happens with Bran, there has been harsh criticism against the show for the way several other characters had their stories end. Daenerys Targaryen turning into the Mad Queen in particular was met with a lot of unhappiness from fans, as there was a shared perception this was out of character for the mother of dragons. This backlash has led to a petition for HBO to remake Season 8 from scratch with different writers to provide a more satisfactory conclusion to the episode, and over 1,600,000 people have added their signatures as of this writing.
Also in the interview, Wright says he originally thought it was a joke when he was told his character would become king. However, he defends the decision, saying it makes perfect sense for this to be Bran's fate. "You never thought of him in that way, but what more could you ask for in a king than to have no personal attachments, no agenda, but have a calm understanding of the entire universe?" Wright professes. You can read the rest of his interview at HBO's Making Game of Thrones.