What is the difference between a baby and someone who has never harmed you?

There isn't any, I can kill both as easily. But why is speaking of hurting a baby such taboo? The baby isn't pure, he is merely unable to act.

Even Jesus, considered by many the champion and savior of humanity whipped up the citizens selling pets at a Jewish temple, and the bible says he never sinned once. The baby hurt its mother during labor. They have both hurt someone and have the potential of hurting countless amounts of others - the mother could have died during labor - no one is innocent or deserving of mercy.

I don't understand the hysterical sentimentalities and lugubriousness that emerges once the subject of hurting a baby is brought up amongst these circles.

Thoughts, if you have any.