I'm a librarian who loves anime, manga, and reading a wide variety of genres.
Clines has tried really hard to give this world a surprising, fresh, and interesting explanation for the existence of zombies, except it turns out that it's not really an explanation at all. The vital part ("If they're dead, then how are they still able to move around?") is still just a bunch of hand-waving and "We'll probably never know the answer."
I think incomplete science-y explanations in zombie stories bother me more than no effort at coming up with explanations at all.