In the days of unthinking kids getting pregnant and abortion being illegal, it made sense for the Law to require that the two of them share economic responsibility for the offspring of their careless act.
In these days of Roe v Wade and the woman's right to an abortion, it makes no sense to enforce shared responsibility. As the woman (and I am only talking about legally responsible adults here) has 100% of the legal control over the decision to abort or give life, it must be her unshared responsibility to raise and provide for HER offspring. No, I don't really mean THAT! I mean that the Law should no longer demand that a biological father, who was not formally in a committed relationship (e.g., marriage) with the mother, provide economic support to the child when he was not a willing participant in the de facto decision to have the child and when he has no legal rights in the decision to have the child.