Why is it that some things are seen as a disability we should try to fix in our children, and others - which are in many ways just as debilitating - seen as some kind of beautiful part of humanity?
Meanwhile, having a genetic condition like haemophilia doesn’t give you any conceivable advantage.
At the expense of those people having to live with all the unmentioned negative aspects of autism.
(To say nothing of whether those are actually positives or not. Personally, I don't see how hyperfixating on something for a few weeks at a time at the expense of all my other responsibilities is a superpower, but hey)
Sickle-cell anemia does though. I wonder if some day there could be a survival advantage for haemophilia. What if we erase the genetic code that ends up saving us from some alien virus, you know?
I'm not saying this is a good argument, just something interesting to think about.
However, I think mental disorders like autism and physical ailments like deafness don't have the same ethical impact. One changes who a person is, the other changes what a person is capable of. It also depends on how bad the disability is; in this case, the kids showing most promise could already hear, though badly, and the treatment let them hear much better. I'm not even deaf but I'd happily take a treatment to fix whatever hearing damage I've collected over the years.
And for what it's worth, eugenics is already with us and that's actually not so evil. People carrying certain genetic diseases choose not to have (biological) kids all the time. Others still choose to risk it. As long as there isn't some large conspiracy about perfecting the human race behind it, eugenics can be helpful.