I guess this as close as I will get to an ending. I've typed up everything I can find in my notebook related to this, and written the things I had floating around.
Basically I think it's definitely true that a lot of normal people sync up with each other and come off in certain ways to each other, and then when a lot of people with autism don't sync up with normal people, or don't come off properly, the results can be very bad for the person with autism.
I don't think this relates to people with autism not having "social skills."
I don't think social skills exist. Or, if I do, I think they exist like God exists--in everyone. They just may not always be apparent. For example, I may have very good social skills when relating to other people who have disabilities, or people who are interested in the same things I'm interested in. I have much better social skills with men than I do with women. Social skills are not contained in a person--they require the right other person.
With work, I think a lot of people can learn to develop their mindfulness and modulation skills so that they can have good social skills (i.e., capacity to connect) with more people--or, so that more people can have good social skills with them. It's the same thing.
Some people--disabled or not--may not be able to learn how to do that, but they will still sometimes meet a person who is exactly like them, or who is very good at mindfulness and modulation, and they will have good social skills when they are with that person.
Other people will just not let other people in. Sometimes it will be because the other person is obviously different. Such people may have good social skills when interacting with people who aren't different. But with people who are different, they will always have no social skills; and when a person who's different is with someone like that, they will "lack social skills" too. (But if they were told by a professional that they lack social skills, they won't understand the two-way nature of the failed connection.)
A person could be going through life, who can't talk, doesn't like to look at people, and is in a lot of emotional pain which they express with "challenging behaviors." This person may live in an institution where no one engages with them because the person is not judged to be interesting, or interested, or capable. One day a new person comes to the institution who is interested in the first person. They start to walk around together and sit together, even though they don't look at each other. Maybe they play games like the two kids I knew who liked to move each other's arms without looking at each other. Maybe they make noises at each other. Maybe they just physically stay near each other as much as possible. This is what life is about, and for some people, it never happens.
But it just takes people who fit each other, or learn to fit each other.
When someone is isolated or bullied, that is not all about them. Other people are bullying them and deciding not to engage them. Still other people, from a distance, in abstract, are framing the person as Someone Without Social Skills, while leaving the other people involved unmarked.
But everyone involved must have bad social skills, because they are all contributing to what is going on. Maybe we can't in the short term stop people from bullying and isolating other people, but we can in the abstract apply the social model of social failure, and stop saying that social failures deserve to be alone.