I think it's because we as a society are trained to revere the maternal, not to say anything against the sanctity of motherhood and the perpetuation of the species. As a mom myself (and a deeply conflicted one, which should be apparent), I can honestly say that kids are a hassle and they make you lose your identity and they bleed so much of you out of yourself. Is my daughter worth it? Yes, but only because she lived in my body and is a part of me. Would I expect somebody else to like, or even put up with her bullshit? Absolutely not. I saw we hunt down this evil woman and put a terrible hex on her--make her pregnant with triplets who turn out to be colicky and say things like "I'm the Baby Jesus" in public (which my daughter has unfortunately done, many times).