Their logic is fine.
If you believe abortion is murder, then rape is no justification for killing the child, and no matter what you think, the legislators think that it IS the same as killing the child.
And yes, then the rapist would indeed have the same rights to the child as the mother. Which is to say, the Mother would not have many rights to the child if she had committed a violent criminal offence. As obviously the rapist has done that, it's hardly going to be equal access. Just that both are judged by the same criteria.
Just consider how many Family Court hearings are actually going to consider it appropriate for the rapist to spend time with the child? Pretty much bugger all.
The fact that at some point the rapist might have some for of connection with the child... is just a fact of life, I am afraid. In these sorts of cases, the well-being of the child is put first and it is considered a human right for a child to, for examp,e, know the indetity of their parents, regardless of circumstance.
But there is no need to perpetuate the idea of a rapist forcibly gettin into his victim's life and taking a child, or what-not.
So the rest of this all flows logically from the belief that a foetus has the right to life.