My mother's kids: Zero were diagnosed as autistic.

My kids: Two are diagnosed as autistic.

Two ways to look at it. 1) An infinite increase in cases. 2) Diagnosis became a thing.

Of note, the most autistic-y of my siblings was more successful than the rest of us combined.

Not mentioned, but there also seems to be a lot less stigma associated with certain diagnoses these days than even 20 years ago. This leads to less resistance to seeking out a diagnosis in the first place which will also increase the apparent rate. This is good when it gets people a proper diagnosis and potential treatment or access to support.

The author is basically saying that autism is mo more prevalent than it was, say, 50 years ago -- it's just that we've gotten better at recognizing it.

The conspiracy theory mentality would lead one to simply assert that he is wrong. I am not a conspiracy theorist. On the other hand I AM skeptical wrt the author's assertion. It is rare for the intuition of an intelligent layman to be so significantly wrong.