No, because seeing the overall ending plot points, and imagining that GRRM will get us there in a much smoother way, is promising.
Because if Jon being a Targaryean, and that not mattering at all, simply cannot be the way the books end up. I refuse to believe that a plot point THAT significant, THAT world-changing, would only be used as another cog in the wheel of Dany going crazy.
I'm actually ok with most of the endings. Jon being a Wildling and living free, away from the Westeros politics, seems like that would make him happy. Sansa, Queen of the North, completes her arc nicely, in my opinion.
However, I'm only ok with Bran being King, if the following are true:
He sees all past events and can (at least somewhat) see future events
He saw Drogon flying over KL
He knew that everything leading up to Dany going crazy was in motion. (Him telling Jon that he was right where he needed to be all along, in order to make this timeline be the one that occurs)
He knew that Jon being the rightful heir would have no meaning, other than driving a wedge between him and Dany, and being part of the reason she goes crazy
He knew that all these events would eventually transpire which would lead to him being King
He wanted to be King (Why? Who knows? Would have been nice to get more info about Bran, AT ALL, other than him flying with the Ravens during the apocalypse)
It's bittersweet, because like I said I generally didn't have a problem with the overall ending. This was and still is, one of the best shows ever, any genre. But it's bittersweet knowing that they had the potential to be the best ever, and rushed it so they could get started on Star Wars.