I agree. It's also eugenics when pregnant women choose to abort a fetus with Down syndrome.

There aren't good arguments against this kind of "voluntary eugenics" that don't appeal to religion or prescribe a transcendant value to human life.

I would not. Antinatalism and childfree movements aren’t based solely on genetic arguments. Corinne Maier, for example, outlines 39 non-genetic arguments. One of these arguments is based on genetics alone.