Pregnancy is different in that the violator does not intend to do so, and has absolutely no agency in the situation. So while yes, the foetus is the violation, it is doing so through no choice of its own.
My analogy compares the profound violation of one's body being occupied and used non-consensually during pregnancy, to the similar violation of rape - the effects on the woman of having her ability to say 'no' to the usage of her body taken away from her.
So no, the foetus is not a rapist. If anything, the society that forces her to remain pregnant when it's medically possible to abort would be the rapist in the scenario.
You're also confusing rough analogy with exact like-for-like, which obviously it's not. I didn't say the foetus was bad, or required punishment - I said that society forcing a woman to endure the non-consensual usage of her body is bad. It's not about the foetus at all. It's about the woman's right to control the usage of her body by another human.
Interesting that you entirely skipped past this part of my comment, except for one small part where you talked about parents, which wasn't what I was talking about:
In no other situation is a human being forced to allow invasive access to their body, even in order to save another human's life.
Even in situations where they might be the reason the other human will die without help (say, an accidental injury) they are not required or expected to forfeit the ability to say 'no' to the usage of their body and donate a kidney, or part of a liver.
They're not forced to donate organs, or marrow, or even blood.
Their ability to refuse or withdraw consent to the usage of their body is total and absolute, even if the other person will die without their help.
Even if the other person is a saint, who does wonderful things for the world, and will be sorely missed by friends, family, and society at large, there is no requirement for a person to donate the use of their body to save another person's life.
So, why is it different with a foetus?