Once upon a time, Analog Science Fiction magazine had a book reviewer named Spider Robinson. His reviews were always valuable, even if you didn’t agree with them, because his stated purpose was to tell you what you needed to know to judge for yourself whether you would like the book or not. He didn’t use stars, or at least not insofar as I recall. You couldn’t possibly encapsulate what he wrote in something as simple as a number from one to five.
The problem with his kind of review is that it is labour intensive on the part of the seeker of new books. You have to scan a lot of reviews, each a paragraph or two, which in these days of “TL:DR” is more time and energy than some people want to invest. Reading a book is one thing. Scanning through a lot of prose to find one book that could be interesting is a lot of work. And few people want to write reviews of that length anyway.
In fact, I often see one star reviews that say explicitly, this book is not the sort of book I want to read. Or worse, this entire genre of books is not something I want to read (in which case, why did you bother to read it at all?) For a seeker of new books, that is an utterly useless remark.
Low star reviews are very often an expression of feeling or prejudice. How often have we seen movies we really like get rating-bombed? I once heard a prominent award-winning speculative fiction writer say that they only read four-star reviews, because those are people in your intended audience from whom you can learn something.
So, it seems to me that in this world of mass communication, the masses can’t really communicate what we want to know. Now, most of the books I buy were recommended by someone I trust (good old word of mouth) or written by authors I know, either established writers whose books I’ve liked, or fellow writers I have met through conventions or online.
Nevertheless, I have been told that writing reviews and giving ratings is extremely helpful to the authors, even if the review is short. I haven’t been doing it much; maybe I can improve. But if I am inclined to give three or fewer stars, I am going to think carefully about whether the book was meant for people like me.
Scholar, Writer, Computer Geek