I can see your point here, but what is to stop somebody from begaving that way and just claiming to have an official diagnosis, rather than a self diagnosis to begin with? There's always going to be people who behave in bad faith in any group, People who are going to lie and manipulate are just going to do that. There's no way to avoid that, that doesn't result in alienating people with systemic barriers to diagnosis. With what we know about the bias in diagnosis to begin with as well as all the other reasons people have pointed out. I think rejecting self diagnosis as a valid means of finding support, and community is going to harm more people than keep out bad faith actors.