This isn't about genuine self-diagnosed people. There are reasons why many Aspies, mostly adults, are undiagnosed. My own diagnosis was a succession of happy accidents, without which I'd probably still have an official diagnosis of "probably depression, or BPD, or OCD, or maybe some other shit, maybe you'd feel better if you lost weight?"
This is about people who claim to have Aspergers purely based on having social problems. Back when I used to hang out on a lot of big autism-focussed online forums, I saw a lot of these people pass through. They were usually young males who considered themselves of above-average intelligence, but who had interpersonal issues. Obviously this was because they had Aspergers, and those useless NT sheeple just didn't appreciate their genius.
But their special interests were almost exclusively "computer games", "boobies", and "your mum", and if the conversation turned to things you have to actually be autistic to understand - sensory issues, motor skills or executive function, for instance - they suddenly had nothing to say. They'd usually been banned by then anyway, for trolling and picking fights. Maybe their social problems had less to to with Aspergers and more to do with being unlovely little brats.
Then I found a rather problematic question on Quora:
I don't have Asperger's, but I consider smalltalk and much of the associated politeness rituals to be a painful waste of time. Would it be better for everyone involved if I start telling people I'm an Aspie?
What possible drawbacks could there be to pretending to have a lifelong developmental disorder just to get out of a conversation? How could there be an ethical consideration in treating someone else's life and disability like a cheap fancy dress costume for your own temporary convenience? How could claiming to have Aspergers while acting like a jerk possibly make life harder for actual people with Aspergers?