I'm not sure why you are equating a single person, who is clearly mentally ill, posting prejudice comments to all prejudice comments as being associated with mental illness.
This is the biggest straw man argument I've heard today.
I’m not sure why you’re talking about mental illness like a vague catch all term when talking about someone, nor why you’d dismiss a person with a statement like “mentally ill person says mentally ill things.”
Research and clinical communities can better determine whether some classification occurs frequently with some symptom. Or were your HN comments meant to further those efforts?
This is the biggest straw man argument I've heard today.