My favorite comment in the lesswrong discussion: https://www.lesswrong.com/posts/DfrSZaf3JC8vJdbZL/how-to-make-superbabies?commentId=oyDCbGtkvXtqMnNbK
It's not that eugenics is a magnet for white supremacists, or that rich people might give their children an even more artificially inflated sense of self-worth. No, the risk is that the superbabies might be Khan and kick start the eugenics wars. Of course, this isn't a reason not to make superbabies, it just means the idea needs some more workshopping via Red Teaming (hacker lingo is applicable to everything).