"for any reason other than to cure a fatal disease" ... what about non-fatal but debilitating ? Sounds like you have a pretty absolutist view here ? What other reasonable exceptions can we imagine outside your rigid criteria ? Why should we not have nuanced discussions of the entire spectrum of reasons ?
Also hard to miss your implication of "agree with me or you are on par with a nazi"
Ask the question would you be comfortable allowing babies to be maimed or killed in a medical experiment to develop a treatment to some malady?
Make no mistake that is what we are talking about here. You are testing a therapy. Because you are editing the genome adverse effects of the therapy are irreversible and present at birth. Those adverse effects may include maiming or death.
So now that we have established what the stakes are, I ask again, what set of diseases do you think it is worth the risk of maiming and killing babies to develop a cure?
I think fatal monogenic diseases could be justifiable. But even there a valid argument could be raised about alternative approaches - ex. Cystic fibrosis.
Once you get beyond that things start getting dicey pretty quickly. Only a hop, skip, and a jump to nazi medical experiments on the “mentally retarded”. Check out the Belmont Report for more formalized ethical framework for medical experimentation on people.
Also hard to miss your implication of "agree with me or you are on par with a nazi"