I'm not trying to argue from authority or get into credibility wars*, but Scott is a professional psychiatrist who has treated dozens or hundreds of schizophrenic patients and has written many thorough essays on schizophrenia. Obviously someone could do that and still be wrong, but I think this is a carefully considered position on his part and not just wild assumptions.

*(or, well, okay, I guess I de facto am, but if I say I'm not I at least acknowledge how it looks)