One issue – especially for high-functioning – is how useful is a diagnosis?
If individuals have developed strategies that allow them to survive and even thrive in the world of neurotypical people, then what benefit is there in getting a diagnosis?
A diagnosis helps when the individual needs support from school, the healthcare system, or perhaps with an employer, since these organisations tend to require a piece of official paper before they can provide any form of support.
If you don't need to access support, such as in a parenting situation, the diagnosis can be counter-productive, because some healthcare professionals have wrong ideas about autism.
A friend of ours who has a son diagnosed on the autistic spectrum has a female chocolate Labrador. She had some puppies, and these were offered to a special school in case they needed dogs/puppies to help the children.
Autistic children often find they relate better to animals than they do to humans.
She was told that the puppies were not wanted, because autistic children do not want puppies that are brown, but would only accept golden labradors.
In this case (we think), the person who gave the decision had a very limited experience of autism, and was not aware that there is a preference for specific colours and textures,but that not all autistic people have the same preferences.