I never understood autism to be noted for extreme orderliness in all cases. Orderliness from what I understand is just one of multiple possible symptoms that, collectively, are termed as autism.

(You can be extremely orderly and not have autism, for example, if you had Obsessive Compulsive Personality Disorder which is different from the more familiar OCD.)

The thing is, while there may be a broader thing for which “Autism Spectrum Condition” is the most accurate label, modern psychiatry can only diagnose a disorder, and that's not just an arbitrary artifact of naming. We don't have the understanding of the mechanics beneath most psychological conditions, including Autism, to diagnose them other than by the combination of social dysfunction and accompanying factors. To the extent that there is an Autism or Autism-like-condition which is not a “badness” in the concrete conditions in which it is experienced it is outside the scope of what we can meaningfully discern.

> "Disorder" is a medical term for "badness", especially weird to apply to a condition that is notable for its extreme mental... orderliness.

I don't see anything weird about that; are you suggesting that there is no extreme of inflexible attachment to order which would be ever be bad?

Autism is understood to be a neurodevelopmental condition rather than a psychiatric one. This would make sense given sensory differences are common and that autism has comorbidity with prosapognosia.