Sure, it makes sense. Especially if you're a parent with a child that is unresponsive, or whose deficits make daily life a struggle. Autism as a diagnosis narrows the field of possible interventions to a manageable chunk, and it allows these parents and professionals to begin calibrating a plan that anticipates the child's needs and development. It helps them understand a possible range of responses to these interventions on the child's part, and more importantly, it gives them an answer to their constant "what is happening" worries. I don't want to devalue the idea of autism as a diagnosis.
The problem is when you move into the segment of the population that says "It's a diagnosis, not an identity." To be frank, that's a dangerous attitude. You see, the term "diagnosis" is itself neutral. You can diagnose problems, or you can diagnose conditions, or you can just diagnose causes. For example, a diagnostic on a computer issue can reveal that the noticed change is not in fact a problem, but a natural side effect of two pieces of software interacting. Diagnosis can be used without automatically assuming a negative connotation.
But what of this idea of "identity"? An identity is a set of distinguishing characteristics that set a group apart. It doesn't need to be used to excuse bad behavior or to create an insular attitude. It can just help people to come to terms with what it is like to be a certain way, as in the use of identity in the LGBT community. It can also be used to communicate a culture, as in identity politics in race and gender studies. Most importantly, it can be a way to find support. A way to view differences without the stigma of disease or disorder.
Identity can help people to move to a place where support services are less necessary, and where their own sense of their natural way of being allows them to measure the difference between themselves and the normative behavior of the dominant social group. (Sorry for the university language, but sometimes there's no better way to say it.) You can see this with the transgender rights movement, especially in the way it separates itself from LGB issues and calls attention to the special needs and characteristics of the trans community.
To me, autism has to be an identity. I'm too old to receive services, and I make too much money. Some people would say that the fact that I can work without support means that I don't need the diagnosis, but they would miss the point. It's not that I don't need support, it's that the support for my needs doesn't exist. Not in any federal program or educational initiative I've found. To be clear, I would not be capable of doing the work I do without the help with life skills that my partner and her family have given me. I would not have advanced to the point in my work that I have without solid mentorship from people who understood my needs and who were willing to accommodate them.
None of this accommodation came from using the resources outlined by the ADA, though. Why? Because for my particular deficits, there are no accommodations. An employer can't make an accommodation plan for "be patient" or for "it's not sarcasm, he can't tell what the tone of his voice is". That kind of understanding comes from good people being good. The thing is, those good people still need to understand why it is that their patience is being taxed. They need reasons. Those reasons are the explanation of the autistic identity.
I work at a university, and I teach in the humanities. This makes the autism-as-identity model of understanding easier to communicate to my peers than the autism-as-disability model or the autism-as-deficit model (which I do believe are different, but I digress). It also helps to highlight why this model is so important:
Eventually, if your children make enough progress, their deficits will no longer qualify for services.
It's a sad fact, but only the autistic adults who are most disadvantaged receive services in a lot of cases. Certainly, where I live, I was basically told that unless I wanted to deal with Adult Protective Services, there wasn't much for me. That was it: either this is a disability and I need to apply for disability insurance through Social Security, or I needed to be in a supervised living situation, or I didn't really need help.
All of those are wrong. Because what I am, the way I think, and the bizarre sensory reality I navigate every day--these things have not changed for as long as I can remember.
I'm just as over emotional as I was when I was five. I'm just better at going someplace private to let it out.
I hate to be touched just as much as when I was very young and I was reprimanded for not wanting to hug my grandmother. I've just learned to scream quietly and inside my own head when it happens.
To be clear: I've not outgrown anything. I've just mastered the art of screaming without my mouth.
To say that autism, or more broadly, being neurAtypical, is not an identity is tantamount to saying that this is a separate thing from me. It is to say that I can somehow be separated from the neurological differences I possess. In its most condescending form, it is to assume that when I'm behaving I'm "in remission" and when I have a bad day I'm "relapsing".
In short, to say that autism is not an identity is to say it is a disability. And while that might be attractive when you're making an IEP, it's also limiting. It's a way of telling someone what they will not be and what they will not do, because they have a limitation that can not be transcended.
So you choose. Autism IS a diagnosis. Whether it's an identity or a disability, it needs to be evaluated by a professional, to be sure that what is happening is autism and not another condition with a different set of needs. Beyond that, you choose whether it is an identity or a disability. Whether it defines what you are, or what you aren't.