To me it's an issue of personal freedom. We live in a society where we have the technology to control our own reproduction. This is an advancement over the animals who have no choice.
Animals have to reproduce because of their sexual instincts.
Humans have the same instincts, but we now have birth control and abortion which allows us more control over when and how many babies we will have. This choice gives us an advantage in that women can control when they will give birth so that they can do so at a time that is their choosing rather than by accident. It also give a woman control over how many children she will have. This allows for babies who are planned and are more likely to turn out better because they are wanted and a woman isn't stuck raising more kids than she can handle. The planet is overpopulated.