That’s not what GP is saying. He’s saying that a term like “autism” is a lasso trying to capture a gigantic number of individual traits and symptoms. This is true of any other “psychiatric disorder” as well. There is no “autism”, there is no “ADHD”, there is no “OCD”, any more than there are tables or chairs.
Something being a table is a label we slap on it to abstract certain attributes, that allows us to reason about it without having to think about all of the non-table-attributes it has. What do tables do? What can we do with them? We can put things on, eat off them. We can’t feed them to our pets. We can’t use them as a trampoline. The object being “a table” is just a categorization we make to allow us to think about the object; it isn’t something that the object is.
Similarly, people aren’t “autistic”. They’re just people, who have certain traits, which psychiatrists have decided should be lumped into a category called “autism”, because they’ve noticed a cluster of other people who have similar traits. So, from this standpoint, someone “being autistic” does not tell us anything. We can already see that person’s traits or characteristics. That categorization might be helpful to some people, and it might be harmful to other people; and they should use or avoid using it accordingly. But they can choose to do that, because “autism” isn’t a “thing” - it’s a mental construct.
It’s the same thing as any condition which deviates from the set of characteristics considered “normal” for a given population.
Eczema is a skin condition which happens to some people, it’s not something that happens in most people. But we can see evidence of varying degrees of severity of skin damage due to eczema. This condition can happen for any number of reasons, immunological, endocrinological, or some combination of factors. There are different types of eczema, but for ease for conversation with anyone other than a doctor, you just say you have eczema.
Same for mental conditions, they have their underlying causes, and some representative characteristics we found on average and grouped them as classes for ease of diagnosis and treatment.
I understand the folly of mischaracterizing, so it doesn’t make sense for researchers or medical professionals to not care about the categorical distinctions.
However, as far as the normal public is concerned, someone’s problem is their problem, and they don’t owe you a detailed explanation of their condition, or a doctors note because you’ve been socially offended (I understand maybe that’s not the point in either of your posts, but I thought I should say it now that it occurred to me in the flow of this post).