I'm curious why people find the diagnosis to be so important. I can't at all imagine identifying with the sentiment, "Nothing is wrong with me, I’m just autistic," as one of the women in the article says. When I go to a party with my girlfriend, I want to come off well, if only for her sake, and I would like to have some interesting conversations, and maybe (very optimistically) to meet someone I can share an interes…
However, for the therapist it might matter more. There's some evidence, for example, that CBT, which is used for anxiety, among other things, can actually worsen the situation in someone who is on the spectrum.
Furthermore, it's kind of unavoidable at this point because a diagnosis is often required for health insurance purposes, as I understand it.