As long as their has been a diagnosis for autism spectrum disorders,it has always been a subjective determination and nothing more.Some pros see it one way and others another.The DSM manuals are mostly a guideline for where to spend money.I have no interest in the ICD as it will never apply to me.Here in the USA where the DSM rules the roost,it doesn't apply to me either because I seek no support. Some of us that are older just had to deal with our quirks because milder symptoms of ASD weren't considered that big of a deal unless you were profoundly autistic. Often in cases like that, a professional's opinion that the client would best be served in an institutional setting and not in the home. If you weren't profoundly autistic,you basically got nothing or some other lame assed diagnosis (subjective professional guess) that was still far from the mark.
The ASD umbrella used in the DSM 5 is supposed to address severity of symptoms instead of the differing names formerly used as the labels. It is very flawed as well in my honest opinion,because the symptoms are not the same in each individual. Even with dna testing,it still all boils down to a professional psychological opinion in the end.
Yeah,I had some relationship struggles all the way down the line and had to teach myself how to conform to society to an extent,but the good parts of my ASD made me what I am today,so I view my ride on the spectrum as a gift and not a curse. I am in no way trying to dismiss the struggles of others,I am only speaking for myself. I honestly believe that anyone anywhere on the autism spectrum should focus on their strengths and do their best to maintain a grip on their weaknesses when it comes time to do battle.
Screw what any damned book says,they are only opinions too