What makes those diagnoses "neurodivergent" and the others not? Why aren't other diagnoses "neurodivergent" too? How exactly do we define "neurodivergent"? (And why is that the right definition to use?)
> They don’t have much overlap with personality disorders (which do have a lot of overlap among that category).
There is a lot of overlap between the disruptive behaviour disorders (DBDs) – oppositional defiant disorder (ODD) and conduct disorder (CD) – and ADHD; so much so that ADHD is sometimes considered a DBD along with ODD and CD. And there is a clear connection between CD in children and adolescents and ASPD in adults – indeed, a child or adolescent with CD can follow one of two trajectories, either their conduct problems resolve with maturity and they become law-abiding pro-social adults, or else the child/adolescent diagnosis of CD evolves into the adult diagnosis of ASPD. So there is definitely a connection between ASPD and ADHD. A child with ADHD (even without comorbid CD) has an increased risk of developing ASPD as an adult – https://pubmed.ncbi.nlm.nih.gov/24284138/
Some researchers consider ASPD to be a neurodevelopmental disorder – https://pubmed.ncbi.nlm.nih.gov/29401045/ – which is the same category that ASD and ADHD (and sometimes also OCD) are put in.
There is also a lot of overlap between ADHD and BPD (Borderline personality disorder) – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4739390/
There's also overlap between ASD and BPD – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5590952/
A lot of "non-autistic assholes" may have other diagnosable conditions, for example narcissistic personality disorder (NPD) or antisocial personality disorder (ASPD). Are NPD or ASPD "neurodiverse" or "neurodivergent"? They are probably partially genetic, just as ASD is probably partially genetic.