Attack of the One-star Bandit

I'm not complaining--some things are inevitable. You walk through a dog park, you'll step in poop. You have your books on Goodreads, sooner or later you'll get hit by a One-Star Bandit. It still can be a shock, especially when your book is still in the editing phase, and not even a single advance copy has been sent out, nobody besides your betas and publisher have read it. Then you check out the person, and it's someone with their profile set to private, and over five hundred ratings to their name at one and a half stars average. Bingo! You got hit by a crusader.

This person clearly has not read your book, or likely any of that five hundred, but they have an agenda, and you are in its path. You start to wonder what it is. Is it about the genre—the person fighting a microscopic moral crusade one rating at a time? Is it something more exciting? Perhaps a frustrated writer down-rating all the books of a publisher guilty of rejecting her/his manuscript? How much time a day this person spends tracking new releases to strike? Does (s)he get an emotional satisfaction out of it?
So many mysteries, so few answers.