He has a point:
This is a problem for book reviews, but I think the critical medium that suffers most is pop music criticism, which skews toward generally positive reviews of most everything, no matter how bland or terrible. Scan the sidebar of Metacritic’s music page. Nearly all of the review averages are positive or very positive, and almost none of them are straightforward pans. In fact, right now I don’t see a single album with a review average that gets a score categorized "generally negative reviews." Contrast this with the movies page, which contains more than a dozen films with low averages. Even the limited release indies — the "artsy" films — are often given low marks.
Is contemporary pop music really that much better than contemporary mainstream filmmaking? I think not. Instead, it’s just that the music reviewing culture has developed in such a way that most everything scores a "pretty good" or a "not bad." (Witness Idolator’s ongoing mocking of Rolling Stone for the rock mag’s tendency to give pretty much anything a three-star review on its five-star scale.) There are a handful outlets like Pitchfork and The Village Voice which regularly publish tough music criticism, but these are the exceptions.
