Because it's growing in her. Because it can't survive outside of her. Because she's the one who has to lug it around. Because of exactly how much of a change it will make.
An infant child can't survive on his/her own. Someone needs to take care of it. By your logic would be ok to kill that infant?
If she makes a stupid mistake?
She will know the consequences of her actions. If she truly doesn't want the child, give it up for adoption and hopefully she would ever make that mistake again.
If she finds out that it's going to have severe birth defects that will probably result in its early death?
I'm gonna give you that one because if that child is sickly or is endangering the mothers life then its better to be aborted.
If it's going to have a life-impacting mental illness that will require her to take care of it for its entire life?
So because it will have a life-impacting mental illness, it should be killed? Is this nazi germany were eugenics is practiced?
That life won't ever know. It isn't aware.
If i slit your throat in your sleep you wont be aware, but that doesnt mean i should kill you.
As far as logical thought goes, it is the equivalent of a tumor that will eventually become a member of society if carried to term.
A tumor cant become a human life.
Now, if there were a way to remove the baby without scarring and let it continue to grow somehow if the mother didn't want it, I'd be advocating for that.
Adoption is an option. If that woman had consenual sex, she will have to bear those 9 months. Give up the child to an orphanage so he/she can at least have a life.
rehabilitated/contributed to society in some way.
Very few murderers contribute to society. Very few.
there's always the doubt that the accused is actually innocent
That is true, and I personally only support it in cases where guilt has been established. Out of curiosity, if someones guilt had been absolutely established and they committed a heinous act eg.(Sandy Hook, Aurora) and we lived in a society where money was not an issue, would you support the death penalty.
Why is killing someone for killing someone else justice?
Deterrence for future crimes, the removal of an evil and sadistic person from society, and justice for the family and friends of the victim(s) and the victim(s) himself/herself.
Eye for an eye leaves the world blind.
That murderer choose when his victim would die. His victim did not have a choice. His victim did not have a chance to live there life. Why should he.