I agree :-) But I suspect the (correct) distinction you made between the two different motivations for criticism are irrelevant to Hacker School because critici

I agree :-) But I suspect the (correct) distinction you made between the two different motivations for criticism are irrelevant to Hacker School because criticism of any kind is seen as an impediment because some groups find criticism intimidating, and a primary goal of Hacker School is inclusivity and diversity. That is why the conclusion of the essay was to stop being so critical rather than be more judicious about what you criticize. I totally agree with them that there is too much worthless criticism, but what works for them can't be a universal prescription. But maybe I'm reading to much into it.