I think the commentary on the state of Givewell's evidence - in particular, that worryingly large parts of it come down to "we called a mid-ranking employee once and they claimed they were doing X and we thought they had good vibes" - was good, correct, novel and important: strong upvote for that alone.

 (I disagree that you should blame Givewell for that: they're not hiding their flaws, and AFAICT the only people other than this author who are openly discussing Givewell's limitations are Givewell themselves. Most of their alleged sins IMO come down to the way people insist on treating them, and the bizarre dearth of competitor/successor organisations aiming for "Givewell but >10x more rigorous/demanding".)

I think almost everything else the author says is some combination of incoherent, incorrect, mean-spirited and fnordful. But in the marketplace of ideas, one bullseye is worth any number of missed shots.