Did you miss that?
Unless either party has an actual set of qualifications to diagnose, then neither should be pronouncing one way or the other.
It could be, it could also be that people are finding a "reason" for their behavioural issues/predicaments.
It's far too complex (even for qualified professionals) to be making broad statements.
The poster is claiming without any evidence other than the "friend" was "self-diagnosed", which doesn't tell us if the "friend" was right, or not, and adding that they knew the diagnosis was wrong because of other claimed attributes.
I'm honestly shocked at the response to me pointing that out.
If you want to go round making judgements on peoples' mental health without any qualification to do so, and post that judgement on social media (which Hacker News is) then I will call you out for that, every time I notice.
People come to these comments claiming to be all about science, all about serious thinking that's not found on other social media, but then this trash gets posted and people calling it out get attacked.
This might as well be on Reddit, or Facebook.