I understand their perspective but it’s still silly.
I’m a competent, highly functional person. I also have idiopathic hypersomnia and IBS-D. I’d love a fix for either; I want to live the best life possible.
The whole deaf community opposition to treatment reads as just a defensive mechanism. Being deaf means that one of your limited amount of senses doesn’t work. By definition, they’re disabled. That’d be like people whole are really near or farsighted not using glasses because they’ve decided not being able to see is their culture or personality. It’s ridiculous, and that viewpoint should be more than ridiculed when deaf parents don’t pursue treatment for their children.
The difference between deafness and other disabilities is that deafness forces you to communicate differently. That communication difference creates a separate language community, which develops its own culture, just as every other language community does. When people belong to a certain culture, that belonging often forms a part of their sense of self.
When it comes to children, then, the question is not just "do I want my child to hear better than I can", but also "do I want my child to speak the same language and belong to the same culture that I do" - something most parents want very much.