I wholeheartedly agree with this Slate piece arguing that book criticism, especially online reviews of books, have become too positive. But this is likely nothing more than a reflection of contemporary reading experiences: who wants to waste their time on something they might not like, or might require a lot of effort? Again, (and I mention this because of my experience with it) the tendency of contemporary conservatives to prefer infinitely lesser but 'safe' works from the 20th century over classics is a prime example--why bother with, say, Goethe*, when Evelyn Waugh will confirm the essential correctness of one's view of the world? The result is confirmation bias masking as objective judgment--"I love this book I selected because I was pretty sure I was going to love it!"--and yet another source of impoverished critical discourse.
(This is related to, but separable from, the tendency to misread books so that they flatter one's own prejudices, of which there are many examples.)
*Not that you have to like Goethe; I'm rather indifferent. But it might still be important to read him.