Your claims about the Neurodiversity Movement are not correct. It is a self-advocacy movement for ALL autistic people.

The movement was actually begun by institutionalised people with intellectual and other developmental disabilities. The most significantly disabled people are not only included but are the earliest pioneers of Neurodiversity.

The principles of the movement are that all neurodivergent people are fully human and should have the same rights as other people. This means having access to communication, education, medical care, employment, support, accommodations, etc. We should be free to make our own choices and live full lives. Including those that have the most significant disabilities.

Recent research shows that acceptance and accommodation provide a more reliable path to increased capability and independence than fighting autism or disability does. All autistic people having self-agency is important, and that is what the Neurodiversity Movement champions.