"That wouldn't follow even if we accepted that personhood is unrooted in objective reality."
Most every cell in a human body is human life and can give rise to a person. In order for a person to become a person the creator, at least the mother must make the decision.
"Why just the parents, when the whole of society is affected by the 40 million lives lost to abortion?
The whole of society is not effected. In the event the parents wait to long to decide, and effective contraception no longer applies, folks have a right to decide when parenthood applies by law in default as a standard. It's the same with the age of reason.
Prove it - take a cell from anywhere in your body other than the reproductive organs and make a person out of it. We'll wait.
Why just the parents, when the whole of society is affected by the 40 million lives lost to abortion?
The whole of society is not effected.
Society is unaffected by 40 million absent lives? I'll let your statement speak for itself.