I don’t oppose the safe drop off sites, I just don’t think they do much good.
Anyone crazy or evil enough to abandon their baby in such a way is not likely to be affected by a safe drop off option.
Anyway, anyone can place a baby for adoption. It’s no crime, never has been. There is no sanction.
So whoever dumps the baby is either irrational or evil. They aren’t thinking about much else.
I suppose that person would be haunted by the thought that one day the child will grow up, and find out who their biological parent was, and have to come face-to-face with them. I could see where people that evil wouldn't want to face that possibility.