Yeah, the label does not address intelligence at all. At this point, on the physical/biological side of it, it mostly means "non-standard brain that we can't categorize". But there are also characteristics that those people have in common, of course, even comparing the dumb to the smart. Some of the characteristics are also contradictory, like how some autists are more dyslexic and some are more hyperlexic (but neither are the normal thing).

I think obsessions can alter a lot too, really depends on what each person happens to get interested in, so it must be a least partly connected to whether or not reading is one of those things. Could have an effect, I don't know, I don't even remember not being able to read (but I do remember refusing to do presentations in school since the very beginning).

Also, of course, every category of person that isn't "dumb obedient slave to society", or a psychopath running that society, or a narcissist getting the population to worship the system, has to have some negative label associated with it, whether it's a problem or not. Though in this case it lost most of the negativity, probably because people started using it that way more instead of trying to fucking ban it as offensive like everything else.