Your opening lines about the assessment 100% reflect my experience. I don't know if I'm autistic, and neither did the assessor! I'm UK based, so I could get my assessment on the NHS but I had to wait 2.5 years on a waiting list. The assessment used materials for children and not one question asked why do I think I might be autistic. Apparently they didn't have time for any of that.
The assessor actually said that she didn't think I'd benefit from a diagnosis, because there's no help available. But it's not about that. It's about explaining a lifetime of exclusion and bullying. I didn't try to persuade her otherwise because I really did want an honest opinion.
None the less, I suspect if she'd seen me when I was a struggling kid, the outcome might have been different. My sister says I'm autistic. No ifs, no buts, and she works with autistic people, so she recognises it.
Me? I don't know. I have lots of traits. And no friends. I relate to a lot of things in autism, but then struggle to relate to other problems where people say they cannot do simple tasks (one person said she couldn't open doors, but then wrote about her experiences where she actually opened lots of doors).
I think it would be useful for autistic people who are angry with the rest of us to understand that even normal people come on a spectrum and at some point, there's a line. I think I'm on it, straddling both sides, accepted by neither.
Having said all that, as I read through the rest of the article and see all the downsides and how a diagnosis can add to your problems, perhaps it's just as well I don't have one!