Because imposing what's supposed to be an elective surgery upon a young child, especially without parental consent, is the very definition of child abuse.
But it does raise another important point, regarding abortion access: what about young girls who become pregnant (either as a result of consensual sex, rape, or incest) between the ages of 12-17?
Blanket bans on abortion with no exceptions run contrary to the ability, in those cases, of a teenager being able to control her bodily sovereignty -- ESPECIALLY when she and her parents have mutually agreed that an abortion is the best option for her.
So much for "parental consent," huh? I guess, if a teenaged girl's parents happen to be pro-choice, their input doesn't count in the eyes of the "pro-life" camp?