I think basically he is saying there is a bit of a dichotomy in stating that communities overestimate their abilities to apply value judgements and then at the same time state that they should only judge people based on their contributions and value to that community.

As much as you might like, you can't really separate some specific technical ideal of "value" or "contribution" from a person's actions on the whole. People are people, and communities are collections of people with human interactions and interpersonal relationships.

I'll also add that the false equivalence between excluding Allan Turning because he was gay vs. excluding people who express homophobic attitudes because they want to exclude people who are gay is just another way of stating "in order to embrace tolerance we must be tolerant of intolerance". Can we all finally accept that for the fallacy that it is?