Ideally, every child would be wanted and loved. Realistically, too many just aren't. In the best circumstances, being a child and growing up is hard. The reasons for abortion are many. Would you sentence a child to being born to a meth-addicted prostitute who will pass on whatever disease(s) she carries? Do you want a child born and endure the fate of Tesslynn O'Cull or so many other children who suffer heinous abuse and murder? How about fetal alcohol syndrome? Maybe just garden variety violent abuse? Neglect? Rape?
Sometimes a woman chooses abortion because she has the good sense to know that she can't protect and raise a child. 
There are in fact thousands of children in foster care, thousands more in abusive homes. Being loved and cared for is a luxury. 
Whatever a woman's reason for deciding on abortion, the decision is hers to make.