Many of the people who write about books are probably engaged in writing their own, and/or would like to publish someday, and with the way things are now, why would one stomp on the hand that might feed them?
Jacob Silverman in Slate asks for more critical response from these book reviewers, though clearly, anyone who is a critic would have to be passionate enough about the work to understand the process by which it is created, and this explains the sympathetic and friendly strain in criticism. His argument seems to come down on how social media is really becoming too friendly for any real criticism. It’s easier to not dwell on a book you don’t like, and far more uplifting (as well as positive to one’s career, perhaps) to review one you do like. This is nuanced, I believe, what he’s asking for, but it’s not like every reviewer is thinking of unicorns and rainbows. Just look at B. R. Myers in The Atlantic. I don’t agree with everything he says, but much of it is right on, particularly this piece.
On the other hand, what I like about this piece from Lev Grossman is that you can almost be certain which book he’s talking about, and it’s a shame that he doesn’t want to come right out and admit it, because the writer in question has so much apparent power in the industry, such that if Grossman did say something, he could imagine losing his position at Time, his publishing contract, his career. Might I add, nothing could be as bad as a book that came out last year with art in the title, but with art nowhere else in the book.