> I'm beginning to think that nobody other than me has spent a significant amount of time with severely autistic people.

I'm going to say that your definition of "severely autistic" is actually mild to moderate at worst.

The definition of "severely autistic" I know of and have seen in personal experience (family) and in my career has nothing to do with "masking" and such.

It's being a late teenager who is effectively non-verbal, who wore diapers until age 12, who has an "anchoring dog", a 150lb Newfoundland that was trained from birth with audio recordings of him screaming or tantrums, that acts both as an emotional support, but as a literal anchor - tethered to him so that when, as many severely autistic people do, he starts to wander based on internal stimuli - the dog can just sit down and tense up and say "Not unless you plan on dragging a very large dog with you that is trained to stay still when it notices you walking away from your family".

Things along those lines.

> they don't even become aware that they're being rude unless they spend active effort in first identifying, then understanding, then trying to fix it.

This is demonstrably not RMS. He is quite aware of this, and quite openly states he has no intention of apologizing for it, let alone "fixing it".