Well, for one thing, it's cheaper for the government to pay for the abortion than it is to make welfare payments, or pay for the child in foster care, or put the grown-up, unwanted child in prison. 

It would be even cheaper if the government were allowed to pay for sex education classes, so that the person in question knew more about the consequences of getting pregnant. 

That's just the financial argument. 

As for "personal responsibility," that concept overlooks the fact that some people have more control over their lives than others. They have better financial resources, better job opportunities, and their education has made them better able to make good choices.