You need to be able to relate the emotions of the book to the reviewer, good or bad. A review should emotionally move a reader to buy, read, or pass on a book. You need to realize that you do influence who buys and purchases books and that your review should emotionally sell people on a book. That's how to get people to like your book.
I don't mean to over emphasis things or exaggerate, but word choice is a big player in this. I don't think I can do it yet, but I understand it.