In my limited experience people labeled DS on their own based on what they saw and their own experience and background (more often inexperience and very limited background). We had people ask if he was autistic, ADHD or assume he was simply just a result of horrendous parenting (I'm thinking of the random strangers glaring at me at the grocery store...). Testing and starting to figure out a proper label for him was THE BEST thing we could have done to help us help him. It also helped DS better understand himself (he's gifted/LD and he had come to the conclusion that he was "stupid" because of the school struggles related to the LD). I say starting to figure out because I see this as a continuous process. Kids change and we change and adapt over time. He has learned to overcome some challenges and mature so we move on to the next thing. The label hasn't changed who he is but it has allowed me to better focus on how to help him. I also don't see the labels as a permanent box that he must fit in.
I would also add that we tested privately with someone we respected and trusted. We have been able to control exactly who and how we share the results with. In our case we chose to share the full report with his school because honestly the new labels were a better fit than the incorrect labels the teachers were assuming.
