They are partly right. In a way, I can only talk about what it is like to be myself: One person, with one particular sort of brain. I can't speak specifically about what it's like to be profoundly autistic, because I'm not profoundly autistic. I can't speak to what it's like to be a parent, because I'm not a parent either. So, the things I can say have to be things that apply to everybody on the spectrum, or to everybody who is human in general, because those things are things I have experiences of. Other things, I can only talk about what I have heard from others, or what I have learned in my research. When I talk about neurotypicals, I am always using second-hand information, because I am not neurotypical.
What I know is this: All of us with autism, whatever type of autism, have a disability; and that disability often presents problems. It makes it hard for us to understand other people, and hard for them to understand us. We are often targeted by prejudice; we have to fight to receive the services we need. We are underestimated because we are disabled, or we're called lazy and rebellious when we're assumed to be capable in areas where we're not.
However, despite all of this, our lives have the potential for happiness. I have seen a profoundly autistic child in serene contentment with the sunbeams coming through a window, just as I might feel when I am holding my cat, with her fur under my fingers. I've had friends and family who love me, just as I might have if I could not speak. I've had things in my life that are pleasurable, satisfying, and purposeful.
While someone who is very disabled may or may not enjoy the same things I do, there are always things that they do enjoy. There can be people in their lives that they trust and love. There can be useful things to do, and interesting things to learn. In short, they can be happy.
What I have heard most of all from parents is that they want their children to be happy; that this is more important than anything else. And if that is possible, is disability really such a tragedy? I don't think so.
I do think that it's going to be tough for parents of autistic children with all sorts of combinations of traits. There is a lot of prejudice in society and a lot of needless pity. That patronizing attitude--the idea that disabled folks are less worthwhile, that anyone's a nice person just for putting up with them--is something that we'll be fighting for a long time. It'll take a long time for us to make the world safe for, and accepting of, people who are very different.
It's going to happen, though, because of parents who want the world to see that their children are worth getting to know; because of people with disabilities who are tired of being second-class citizens; because of allies who simply believe in the worth of all human beings and know that a society's worth can often be judged by how it protects and empowers its weakest members.
I propose, then, that those who have severe disabilities, and those who love them, should advocate for acceptance--for a world which has a place for everyone in it, no matter how different.
(Re-posted from a reply to a comment in a recent post, because my reply ended up being much more general than the comment I was responding to, and generally spread out into related matters, as my scatter-brained style is wont to do!)