Simen, I've got a few points to make.
Firstly, every single professional diagnosis of any condition medical disease or whatever, starts with the decision, on the part of the "patient" or that "patient's" parents or carers, to seek a diagnosis of some kind. Very often the "patient" approaches the professional already with a good idea of what the diagnosis will eventually be. I'm sure if you have had any experience of getting a rare or uncommon medical condition properly diagnosed, you will know that you just about need to diagnose yourself to get beyond all the fobbing-off and idiotic misdiagnosis by our friends in the medical profession, to finally find a spcialist who knows their job. I'm sure that a great many adults (especially females) who have been professionally diagnosed in adulthood with AS, have only obtained a correct AS diagnosis as the result of their own tentative self-diagnosis combined with good luck and persistence.
I don't know if you have read much about schizophrenia and the so-called schiziod personality disorders. It's quite clear from what I've read, that people who meet some of the central criteria for AS, and who display no evidence of psychosis, are still, in this day and age, diagnosed as "schiziod" or "schizophrenic", and may even be medicated as such. Have a look at Grinker's book and you'll see what a total F-up the diagnosis of high-functioning autists has been in the past (and probably still is in many places). You might also like to check out this list that I've compiled:
http://incorrectpleasures.blogspot.com/2...ative.html
As you can probably tell, I have no sense of awe at all for the supposed superiority of professional opinion compared to the opinions of well-read, objective, and educated amateurs.
Regarding your protests that we are diagnosing people that we cannot observe, well in the age of almost limitless electronic media access, this is not true. I think someone on this thread wrote that they had observed Tim Burton, I assume in some mass media programme. I'm sure that most famous people have some footage of them that can be viewed in the internet, TV, video-hire, DVD-hire, public libraries (that loan all kinds of stuff) or through purchase of media products. Look at the references section of my list and you can find links to moving images that you can view over the net of Bill Gates rocking and also some of Glenn Gould being Glenn Gould. I've recently realized that a hugely well-known female Australian journalist appears to be AS. I've seen her body language innumerable times on TV over a span of decades, and it's plainly obvious that she has hypertelorism and a monotone voice. A while back I was watching a documentary in which my favourite Australian musician was interviewed, and I couldn't help but notice his utterly deadpan voice and body language (that he has always had) and they way he rocked his way through the interview. Knowing that he has a BIG reputation for behaving in an Aspergian manner, what am I supposed to think?
The DSM does not list all autistic traits, in fact it specifically leaves the neurological and physical aspects of autism out of the diagnostic criteria for AS. Motor clumsiness and sensory oddities are not mentioned in the DSM criteria. I'm sure this is because the DSM is written by psychiatrists, who do not wish to cede any diagnostic territory to neurologists. I believe that it is some of the "neurological" and physical aspects of autism that are the hardest to concoct or misjudge and are the most specific to autism; the sensory hypersensitivity, the odd-sounding voices, the very pedantic or very sloppy verbal pronounciation, the weird body language, the odd posture (which is unchanging), the minor birth defects that are often found, etc. Most of this stuff can clearly be seen or heard through a TV broadcast. Only a professional actor in the same league as Dustin Hoffman could simulate all of this stuff at the same time.
I'm not sure if you have had a look at my big list. Every name on it has been included because some other writer has stated or speculated that the famous person is or was on the spectrum, and quite a few living people who have been reported in the mass media to have been formally diagnosed are also in that list. The big list does not reflect my own personal opinions or speculations. I have another separate list for that stuff, in which I give (most of) my reasons.