I think there's a communication issue with regards to how a syndrome is portrayed in non-technical media. And it doesn't get any better when we replace "syndrome" with "condition" or "spectrum disorder" or what have you. A syndrome is just a description of what a black box looks like to us from the outside. We collect different outward expressions (symptoms) and give some sort of statistical baseline - e.g. a certain collection of symptoms clusters together in 70% of cases. In the case of psychological/neurological syndromes - our most poorly understood black boxes - we then create tests which are effectively subjective surveys, aggrandized Turing Tests. And to complete the picture, we also try to cluster with regard to treatment - assuming that if X modality treats Y cases well, those Y cases are all of the same syndrome.

All this is to say that while there might be one "source insult" that creates most of what we cluster as Autism, it is extremely unlikely. There are probably multiple different insults that create multiple conditions that we crudely cluster under the same Autistic umbrella. It is useless to try and define what is the "true" Autism - we need to understand the underlying mechanism first - maybe then we can give whatever we do understand better its own name.

As to why we are quick to label, I'll just say that in my country, as a child psychiatrist put it to me - before the mid-90s parents were angry with him when he made the autistic diagnosis, a trend that was then abruptly reversed and parents started to demand he label their neurodivergent kids autistic, even if he didn't find the diagnosis to be accurate. What changed? The country started to give disability benefits to parents with autistic children.