Allowing the government to dictate reproductive choices is dangerous. Let's say, in the future, we have a government that decides to tackle over population by forcing women to have abortions and both men and women to be subject to mandatory sterilization. It's happened in other countries. Would you like that? This kicks the door wide open for it.

We make exceptions in the law for killing other people: self-defense, warfare, and execution of criminals. The law does not necessarily reflect morality. If it did, we'd be punishing hedge fund managers and adulterers.