This has been on my list for so very, very long. I think I've seen it on various lists through the years, as I had this nearly guilty feeling that I'd never gotten around to it plus extremely high expectations. A la this post's title, those expectations were not met.
Again, the lack of focus in this book comes down largely to world-building. The notes at the back that explain how the book was initailly structured to much to explain why the book is the way it is, but that doesn't really excuse it. The main characters jumpto conclusions or discuss matters in a way that would only make sense if they were hving outside discussions not shared with the reader-- which is not at all the structure of the book. The book may have started as a writiing exercise, but the authors certainly had time to go back and add the relevant details in places that made sense.
I decided slightly over half-way through that I wanted to put it down and not finish, but then decided I would, because it was a YA book and easy read, even if not particularly brilliant, and it would allow me to check off one of my 2017 to-do boxes, and one I had thought I would have difficulty with. So I finished, but I can't recommend it.