There's no clear boundary but one criteria for some mental illnesses is that it causes problems for the person's life. So a high functioning autist could be per

There's no clear boundary but one criteria for some mental illnesses is that it causes problems for the person's life. So a high functioning autist could be perfectly healthy in a world without informal human interaction. Pedophilia is not a mental illness unless it gets you into trouble, then it is. I'd guess the reason for targeting autism is there would be a disproportionate number of highly capable workers hidden in that group which would be missed by normal hiring practices. You wouldn't expect that from, say, schizophrenia or most other neurodiversities.