"Murder" itself contains a moral judgment and is actually banned.

Some forms of eugenics are routinely practised in the West already. For example, pretty much every IVF clinic out there will recommend patients to scrap embryos that are proven to be aneuploid. (So either not viable, or, in some cases, viable but with Down syndrome.) This is accepted everywhere I know and is considered a part of your reproductive rights.

How is this not "good eugenics"? How would you frame it as unethical?

Well if I come in the middle of the night at your house with a gun, you killing me is different than me killing you.

"Eugenics" actually just means attempting to improve the genome our children will have. This does not need to involve forced sterilisation or indeed the government at all.

E.g. giving all parents free genetic screening and genome correction for their fetuses if they wish it would be eugenics.