Given that autism is a huge umbrella spectrum something like you are suggesting would make a lot of sense where there are an additional few descriptors. I can understand someone not wanting to be treated like they have a disease and I would certainly never characterize it as such, but my son can't speak, can't tie his own shoes, can't make his own meals, needs help brushing his teeth, etc. For him (and us) it is very much a disability. That really shouldn't be so hard to understand, and yet for many people on the spectrum who don't experience that and don't know those kinds of autistics, it does seem to be.
They also seem to be sure that since they were born that way, that all autistics are, which isn't the case. My son had a very distinct and severe regression that was akin to someone flipping a light switch. About 30% of autistics are similar, and they do seem to be the ones who experience the most severe disability. That's what finding a cure represents to me - figuring out what is triggering those regressions. He went into a cascade that essentially set off an auto-immune disease that affects his brain. The people who've experienced that sort of thing aren't writing about their experiences on the internet. To say most autistic people don't want a cure is to really mean, most autistic people who can write and have access to a computer and to places where they can discuss that with other people with similar experiences. It completely erases those who will never be able to do that. This is a big part of my issue.
For many years, my non-verbal son was obsessed with watching movies about characters who couldn't talk, such as The Trumpet of the Swan, about a swan who has no voice. He is pretty comfortable in his own skin, but that doesn't mean that he wouldn't want to have different opportunities if they were available.
I don't think we're anywhere close to definitively figuring out what these regressions might be caused by, but I'd sure like to keep looking without people who were "just born that way" taking it as a personal affront. Perhaps that distinction is what needs to be a part of the additional verbage.
I agree that high and low functioning are too reductive. My son is very intelligent, very highly empathetic, funny as can be. He's got many gifts, but being able to navigate the world by himself is not one of them. You are absolutely correct that accepting him in some way that we don't already (there really isn't such a thing) wouldn't address any of those things that make it impossible for him to live alone, or even be left alone. We're able to afford help, and we still struggle at times to get enough respite because our son is also highly OCD and at times oppositional. Most people can't afford the support we get. As tough as it is at times, we are in better shape than probably 90% of parents, many of whom are mothers raising their children alone because their marriage couldn't take the strain. I honestly don't know how some of them manage...
I wish there were some ways to talk about these things that are undoubtedly very different than the experience of autism that most militant advocates have had, but every time I try to do so, I get shouted down and told I'm reprehensible, so it's very rare for me to engage is a conversation about it anymore, even by way of education about another sort of experience of autism. It's mostly just not worth it, although sometimes I just can't contain myself and have to point out that there is not one universal experience of what it's like to be autistic.