I'm in general agreement with you. And <<-- I think he's right to complain about US Universities on this. There was a period quite recently where literal invitations to self-criticism were required at some of the US' top schools. I cannot believe this increased the diversity of opinion and thought at those schools. To me, Summers is a stand-in for a lot of academics in the essay, and most interesting because he was a powerful person who was not as powerful as the social movement of the time.
Anyway, as you say, Mr. Summers will be fine.