It's obvious Goodreads is nothing but a big joke in terms of legitimate reviews if you look at rating averages.Hundreds, if not thousands, of books have fallen victim to one-starring "carpet bombers", who have obviously NOT read the actual book, but for whatever hypocritical troll reason have decided that book/author deserves their wrath.
As a book reviewer who actually USES Goodreads for reviewing books, I encourage all of you to NOT use Goodreads rating averages to determine whether you will read a book or not. Take a little time and actually scan through the reviews. You can tell easily who are real readers and who are not. All it takes is one click on most one-star reviewers' profiles to see that's what they do. Most have hundreds of ratings to their names with an average between 1-2 stars. Those are NOT readers. Readers actually read and talk about the book.
I'm pretty sure this is the case with most every review site. Just do your research, people. You can't trust ratings any more than you can trust Obamacare.