Babies are lovely but altogether helpless creatures.
Wouldn't it be better if tiny humans were born able to walk, like horses, or generally were readier for the rigors of the world, like, say, chimps?
Among primates, human have the least developed brains at birth, at least when compared to adult human brains. If humans were born as far along on cognitive and neurological scales as rough and ready chimps are, though, human pregnancy would have to last at least twice as long. Eighteen months in the womb, anyone?