What an utterly backward and disgusting viewpoint, that kind of world view is abhorrent in 2017, let alone in the late 24th Century.
Just to be clear, whose viewpoint are you talking about?
The Federation should not be a society ruled by irrational fear. The only reason it exists is because it overcame fear of the new and different. And a culture being paralyzed by the same unchanging fear for a thousand years? That's a dreadful notion.
I don't see it as irrational. If genetic engineering / augmentation becomes too widespread, there will be those who believe it will also become mandatory (re: Gattaca). Why should they not fear that?