Let me start off by saying that I do not regularly watch, read, or listen to reviews about books that I want to read, or that I am currently reading. I feel like it taints the experience for me, and I like deciding for myself how I feel about a book.
Recently, though, I have been updating my Goodreads page and seeing the star rating for some books, and decided to take a look to see what others thought of these book I am loving. I wanted to read the bad reviews, and those seemed to be at the top most often so it worked out. Yes, I felt a slight pang that others did not love it like I did, but the reasons that they didn't love it seemed lack luster, in my opinion.
There were reviews saying the topics that were discussed were not done to their satisfaction, that it was too cheerful for such serious topics and the happy ending was annoying (all paraphrasing). Everyone is allowed their opinions, I am totally for that, but I also feel that people have to put things into perspective. Novels are fictional for a reason. Authors have the right to twist things to fit their story, and it does not mean that they are doing something wrong. For instance, zombies and vampires, both of which have been done several different ways: slow vs. fast and sparkly vs. burning in the sun.
If the synopsis says one thing and the book is another, then fine. The book should receive a low rating for being deceptive, but if they match up and the person reading it just expected things to be the way they wanted them then that is not the book's fault. It did not give you what you wanted because, in your mind, it should have worked out the way you wanted it to.
This is when I have a problem with low reviews. You didn't like it, fine, give it a 1 or 2 star rating. On the other hand, when you give it that rating because it did not give you the information you wanted or treated issues a different way than you would have then you're punishing the book and author for not being in your head.