Lots of magazines only publish positive reviews. They don’t say “You must love everything.” It’s much more insidious. They’ll send a reviewer a pile of books and say “Here’s a pile of books. Write reviews of the ones that are worth it, get them to us by Friday and we’ll pay you $50 (or $100, or $25…) per review.” The corrolary is that they pay nothing for the ones you don’t review because they’re not worth it. The reviewer is then in the unenviable position of having a pile of books they have to spend time reading before Friday, knowing they’ll only be paid if they produce a positive review. Lots of people can find something nice to say about anything if it means the difference between being paid and not being paid, eating and not eating. I was sometimes in this position when I reviewed for the old British RPG magazine Arcane. I tried hard to be ethical and often succeeded. Only publishing positive reviews is as terrible an idea as it was when Orwell wrote against it.
Beyond that, there’s an extra layer if you are a writer reviewing—and this is why I stopped writing about everything I read. If you are a writer, there’s a way in which all the other writers are your competition. This is quite different from them being your friends. You’re competing: for awards, for review space, for attention, for sales. I don’t think it’s a zero sum game like this so that if someone buys my book they don’t buy someone else’s. But some people do. In this worldview, if I trash someone’s current book, not only am I hurting their potential sales, but they imagine I am doing it on purpose to put down a rival. The fact that this never occurred to me before someone accused me of doing it—on my livejournal ages ago, not here—is irrelevant. That was their perception. And I can only deny intentionality. I’m a midlist writer. I’m also a reader. From my point of view, I was a reader warning other readers to avoid a bad book. From that author’s point of view, I was one midlist writer putting down another midlist writer to my own potential advantage. This is so repulsive a thing to have thought about one that I’ve been extremely careful ever since.
And, there is more in Walton’s piece; take a look.