I try not to be a hater. But, given how this thread left off, I am wondering if many others feel the same way as me?
Be It Resolved: I think the inability (or unwillingness) to bring a story to resolution is a symptom of a real cynicism, or maybe lack of perceived accountability, towards the audience.
I mean this not only in the macro sense, ie, the unwillingness to finish the series ("Hey, I made my money optioning it to HBO. I'm good."); but also in the micro sense: the entire series (as far as I read, about 2-1/2 books in) was just a series of cliffhangers and inelegant pathos—salting the land with the shock-killing off of key characters as his go-to plot device.
Don't get me wrong: He's obviously a talented writer. Just like Andy Kaufmann was a talented comedian. But, just as with Andy, at some point, the joke is on the audience for paying money for the privilege of being punked. This is why I almost never invest in a "Book One of..." anymore, unless I have independent verification that the initial novel could function as a standalone—that it is, in fact, a (finished) story.
Another author whose work I've enjoyed much more, Patrick Rothfuss, has fallen into this category, too; although, he's roughly a quarter century younger, and he's been active in various other projects and philanthropic endeavors, so I still hold out hope that he'll finish his Kingkiller Chronicle. A Midwesterner who went to Wazzou, maybe he gets things done, lol.