Pitchfork doesn't review music, it reviews context. They're sort of documentary writers, where the score is related directly to how much of a narrative they can wrap around the music being reviewed. Plenty of good music gets sub-par scores because the reviewer can't find 'the story'. Just making a good tune is not enough: it has to be representative of some part of the musicians life, otherwise why bother?
That said, ignoring the 'shimmering shards of icy glass through lasers' type of writing, I often agree with their reviews. Even if they assume way too much into the music-making process.