I saw so many angles when I saw the header to this post ...
I think in a more quiet, less crowded, less chemically impacted past it may have been easier to be ASD simply because the environment was more suitable.
I also think that negatives effect that can come with ASD are more prominent in the current generation.
However I also think that those with ASD have better prospects than ever. Few kids are fully withdrawn; they are engaged in their world at levels that would have been considered impossible 50 years ago. We know how to reach kids and help them in ways that were not available just 20 years ago.
But none of those were the question you wanted answered.
I think having ASD be the "condition of the moment" is both a blessing and a curse for ASD individuals. For the community as a whole I think it has been positive, but the best answer in different situations and among different groups definitely varies. I totally agree that it should be a person's choice who knows and who doesn't. And also how far to pursue diagnosis. My son actually does not have a medical diagnosis; he has a school use one. Which means that once he is out of school he can abandon it, should he choose. He won't choose that; I know he won't; but when I realized that I was in the unique position to leave him with that choice, I figured it was the best of both worlds (although we may be tripped up the changes in the diagnostic criteria, should he want to make it medically official, given how well adapted he is at this point).
Ideally, everyone is allowed to control their own destiny. Sometimes there are reasons to modify that, but when there aren't, your choice.
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Mom to an amazing young adult AS son, plus an also amazing non-AS daughter. Most likely part of the "Broader Autism Phenotype" (some traits).