Eh, Goodreads has always suffered from the same problem that plagues every other review system which uses "score out of X" ranking. Humans just aren't very good at ranking things on a normal distribution, so you invariably end up with every item (books in this case) being ranked somewhere in the 3.5-4.5 range (since Goodreads is out of 5). For IMDB the rankings all hover around 8ish. When in reality the average book…
With eg movies a much greater investment is required to tell if it's terrible.