Well, I look at it a bit like this. I live in Australia, and when I was a kid, the two main carmakers in Australia, and archrivals, were Holden and Ford. From when I was eight until I was fourteen, my parents had a Holden and a Ford (my Dad had a Datsun Bluebird for about five months (he had a brand new Falcon, but one of his colleagues had a Datsun Bluebird and complained that he wanted a Falcon, so the company, instead of telling him to accept the Bluebird, took my father's Falcon from him and gave him his colleague's Datsun Bluebird, which STUNK of cigarette smoke, for three weeks, then gave him a rusty old XC Falcon, for four months, then he had a Falcon station wagon for a week, then he had the Bluebird until the company was sold to Rothmans and they gave him a Falcon) and as most of the bullies had and liked Holden cars, I found myself on the Ford side. My father's Rothmans' Falcons were more comfortable and as I was six feet tall when I was twelve, the Falcons had more head and leg room than the Commodore, as well. I have found, though, that there are some douchebags who drive Fords and some nice people who drive Holden cars.
In every sector of the community, you'll find douchebags and you'll find decent people. In Australia, there are douchebags who vote Labor and decent people who vote Liberal; there are some douchebags who vote Liberal and decent people who vote Labor.
I went to school with a kid who liked Holden cars and supported Liberal, but my Economics teacher said, with chilling accuracy, that the kid, politically, was fascist. I, on the other hand, liked Fords and supported Labor, but unlike this kid, I didn't ram it down other people's necks. If you were talking about a car, this kid would ram it down your neck that he liked Holden and if politics was mentioned, he'd tell you that the party you supported was no good, if it wasn't Liberal. Okay, the kid was neurotypical and I undiagnosed autistic.
Friendships between autistic people form on the bases of not just common interests but common values. Two people can like Fords but vote for opposing political parties and hold vastly different social, religious and other values. I mean, former National Party leader, the late Tim Fischer, and I have opposing political opinions, but if I had been a Labor politician, in the last years of Tim Fischer's career, we would have shared common ground of opposition to racism and opposition to One Nation (a right-wing fringe party of crackpots) and support of autism. Tim Fischer also supported social justice and he was someone who, even if you didn't vote National, if you had a problem, he'd try to help.
I tend to get on well with fellow autistics who share my political values and opinions. I have a lady I'm friendly with who has an autistic son, and while her son likes Holden and I like Ford, we share the same values.
One reason, which helps solve a paradox for me, why I also tend to get on well with Asian people (okay, my doctor, optometrist, cardiologist and pharmacist are Asian) is that some of the characteristics of autism that are considered weird in Western society are desirable in Asian countries. For example, while I have some reservations about the "Tiger Mum", studiousness in Western society will have you labelled "a square" (the first time I heard that, I said, "What? All up, I'm rectangular," thinking, "When you die, they put you in a rectangular coffin and you sleep in a rectangular bed, so where to they get that from?"), a "nerd" or the like. I tended to have friendships with Asian students, because we were typically seen in the library at lunchtime. I remember one smart Alec kid saying that another Asian girl and I were a "couple of square bears."
I have long said that if I wanted a girlfriend, she would have to be autistic, as a neurotypical might find a relationship with me being very lonely. In a sense, it would be like a traditional Japanese man marrying an Italian woman. Why? Well, Italian people are very tactile people and when Italian women catch up, they'll hug and kiss, whereas, in traditional Japan, you bow, and that's it. If I wanted a live-in girlfriend, I would say, "Okay, we need three bedrooms. One for her, one for me, one for intimacy." An autistic woman would understand that, a neurotypical might think, "What? Don't you love me?" or, "That's a bit weird."
So, just like two Ford fans can have being Ford fans in common, or two Australians may have being Australian the only common ground, two autistic people may have autism as the only common ground. True, two autistic people may have the common ground of not liking to be touched, and the like, but if they don't have some common values, they won't get on well together.