He's responding to material accusations; "they claim that his social behavior has prevented more people from joining."
And if you're evaluating a spokesman, which is a role Stallman has to fill, being unusually awkward is a strong disqualifier.
So he's not bringing this up from nowhere.
> I don't know if it's true and already public, but how can you write that publicy about someone, you must be a profesional to diagnose someone and still that's very personal information.
I don't like charges of mental problems. I think when people go for a cheap shot it's usually one of the holy trinity of stupid, crazy or mean. And people like to dress a cheap shot up with some Latin or Greek; worse still is when a pro does exactly what you're complaining about.
In this case, though, he's sticking to what I can condone. I've already pointed out how it's relevant, and that he's bringing it up to respond to charges others have already made.
The other factor is he's not trying to pretend he has any medical qualification or that they even matter:
> He is socially inept, whether incapable because of his Asperger brain or poorly socialized because nobody taught him manners is a moot point.
It's okay to observe someone is socially inept as that's something most adults can intuit. And he also tries to humanize Stallman:
> He has mental issues and nobody cared enough about them to help him.
That's indicting people around Stallman more than Stallman himself. Because of that, I think this is acceptable discourse.