I think he's written himself into too many corners, it's too much work to finish it now and wrap everything up in a way that's going to make people happy and make sense.
It's a shame the tv show turned into a steaming pile of sh*t and the book series is never going to finish. Not much of a legacy to leave.
I think anything geeky with a massive rabid fandom ruins the end product if the creators engage too much with the fandom.
They end up writing for the fandom and lose track of their own vision, everything becomes reactive.