It is no joke, and I am not justifying abortion. But the question remains, “Why were women seldom to never prosecuted for obtaining an abortion?” Not having an answer tells me you have not really examined your own thinking.
Because folks are weak when it comes to holding women to account. Don’t women get less punishment than men for killing born persons? Also, the victims of abortion are much less visible than post-birth victims of non-abort murder. There’s no chalk outline.
Freegards
I gave you an answer. If the mothers were culpable under the law but were not prosecuted - which is your claim, I don't know it to be true - then it's because the police and the district attorney were uninterested in doing their job.
Their failure to prosecute, though, does not mean that abortion is not killing.