Yep @Itisbetter, it's good to be able to talk with people with comparable or similar experiences. This is why I said upthread that I wish people weren't jumped on so hard when they tried to find adjectives and descriptors like "severe" or "profound" or "low-functioning" or "non-verbal" to try to get their meaning across, without many useful suggestions being given of other ways they can briefly communicate how the individual they're talking about is affected.
My feeling is that from a logical categorisation perspective, adding some kind of modifiers to a broad diagnosis, to allow easy and quick communication, would make more sense than re-splitting the category.
Firstly, it's normal for things which are considered the same disorder medically to receive the same diagnosis regardless of severity, or to have subtypes that are expressed differently or happen in slightly different ways. Autism probably has multiple aetiologies, but looking at families, it would seem that at least some families have a heritable type of autism which can result in individuals with Asperger's type, classical type, and various other expressions all within one family, and it seems odd to have a family all inheriting the same basic thing, but ending up with different diagnoses because people wanted it to have a different name when it hit a certain threshold or fulfilled certain criteria.
When it comes to the different aetiologies, hopefully at some point they will be sorted out through research, and we'll know whether all these autisms are different causes of the same thing, or different things, and diagnosis can then be arranged accordingly. We probably need to wait quite a while for some of that, though.
Secondly, there's a question of how to split it. If you, for example, selected traditional "low-functioning autism" as the separate category, you would exclude people with extreme difficulties but an IQ over the threshold. If you wanted to exclude only people who would've had an Asperger's diagnosis in the past, you'll still have an awful lot of high-functioning adult autistics in the autism category who are clinically indistinguishable from those with Asperger's, unless you ask their parents about speech delay. If you split at threshold x, you'll always get people who feel they/the person they care for should be on the other side of it, or would get more/better/different help, or less discrimination and prejudice. If you split at two thresholds, probably even more disgruntled people. And to split, you have to either choose a yes/no criterion, a point on a linearly-measured criterion, or multiple criteria of either or both types, in which case you're going to hit problems if someone meets some but not others.
And however you split it, you have the problem that ten autistic three year olds who fit in the same category will potentially grow up into ten adults with radically different outcomes, meaning reassessments might have to happen and diagnoses be changed, which is more disruptive than moving category within the same diagnosis.
Thirdly, it would be yet another huge overhaul to diagnostic services, other service provision, research, and public awareness, that would all take time and effort and money.
I think there's more room for fluidity, flexibility, and multiple overlying categorisation systems if the diagnosis is kept broad. You could give an ASD diagnosis, and say that someone has profound symptoms, or is level 2 for support needs, level 4 for difficulties with communication, level 2 for sensory-seeking, level 1 for age-appropriate self-care, has/does not have LD/ADHD/DCD/SIB, or however you wanted to subcategorise it. The big chunk of people in the middle would be better served with a more flexible, multifaceted system IMO.
It actually makes little difference to me personally whether my diagnosis is DSM 5 ASD Level 1/ICD-10 Childhood Autism, as it is currently, or is changed to Asperger's syndrome or some new, more politically-acceptable name. I'm not likely to be near any of the new dividing lines, and I don't need to use my diagnosis regularly.
I'm not arguing for retaining the broader diagnosis for my own benefit, but instead for the reasons I've mentioned. (It would, though, likely benefit family members of mine, who I don't want to talk about online.)
(I also think there's far more room for public awareness of the middle area — I know that parents on this thread have commented on the public perception of autism as being all about Chris Packham and Greta Thunberg and people who can go on TV Asperger's dating shows, but showing people with this kind of presentation was in part a backlash to the existing picture of autism in the public imagination before Asperger's syndrome began to be diagnosed in the 1990s. Apart from bloody Rain Man, this tended to be of only very severe classical autism, often as it appeared before any modern interventions, and often in people who were institutionalised. People who would probably receive the proposed separate "profound autism" diagnosis do still get some media coverage: off the top of my head, Louis Theroux's Extreme Love — Autism documentary about a decade ago springs to mind. But there's a lot less about the autistic people who are neither as profoundly affected as that, nor able to live an apparently perfectly normal, if perhaps a little unusual, life.)