Parents are programmed to want the best for their kids, regardless of what they get in return. That's what love is supposed to be like, right? But in fact, if you think about it, that's kind of a strange belief. Given what we know about the way people really are. Selfish and shortsighted and egotistical and needy. Why should being a parent, in and of itself, somehow confer superior-personhood on everybody who tries it? Obviously it doesn't.