Not OP, but presumably it's because it could cement a permanent divide between classes. We still have quite a bit of upward mobility in the US, but health is a tremendous predictor of future outcomes, so gating that to the rich is dangerous to the stability of society in that way.
This seems like more of an issue with accessibility of the treatment than the treatment itself
If we could make most children smart, productive, ambitious, courteous, civil, conscientious, honorable, strong... the value to society is probably high enough to justify covering it for almost anyone.
The society already can invest a lot (through public education) to “make most children smart, productive, ambitious …”.
Somehow society (or indeed parts of it) decided to use it as a tool of further segregation rather than overall prosperity. I’m afraid same might apply to this.
We "invest" more than almost anyone. 38% higher than the OECD average. I don't find discussions about throwing more money at the problem to be constructive so much as a way to ignore other issues at play.
I don't really see how this affects e.g. what I do for my children. I will absolutely be turning them into the closest to superhuman the current state of treatments lets me, traveling internationally if I need to. If someone else decides to segregate access to treatment, that is a separate, wrong act that will not hold me back from giving my children every advantage possible.
(Yes, I understand this is a positional arms race, but 1. that doesn't change the individually-optimal outcome, and 2. that doesn't change that society net benefits from it.)
I don't mean to invest as to spend more money, rather to spend money better and in a more equal way. While USA spends a lot of money on education I don't think it translates in better education on average. Even if this was beneficial for the society in general.
I am, afraid, that this kind of genome modification will further increase divide in a society and turn social lifts off even more. I.e. it's not gonna be your kid to get "improve" brain genes first, and later your kid wouldn't get a chance to get it ever again for their children.
Just to be clear I'm not against of the progress, this thing is fascinating and really shows how awesome humans are. And I get why you'll get it if possible for your kid. I'm just not sure its benefits for the society mean it's gonna be anyhow affordable for regular people.
This is already true to a great extent. A family with lots of genetic health conditions are probably going to remain poor.