Because those are people who are fixated with their own genetics or family name or race or culture.
When we were adopting my daughter from China five years ago, a guy I worked with said to me, “Wouldn’t she be better off with her own people?”
That was one in a long line of comments from a few folks.
Ultimately, the person who raises you is your parent regardless of biology.
Anyone who implies differently with regard to your choice to adopt is a fucking moron.
I could eloquently go on in further detail about this (as I have in previous posts), but I’m gonna stick with “fucking moron” for the sake if brevity.