Because they can't read or write. In all seriousness though, I still think they're stupid. Take their incessant crying for example. What good does that accomplish? You look at the baby's face and you think that it's going to implode from all the strain. You try everything you can think of to make the little monster stop, but it just keeps going. Then, you find out that the only problem was that it had some gas in its gastrointestinal tract. Talk about your ultimate hypochondriac, or what?
I have the solution. I call it the Cry Collar. Essentially it's just a regular old bark collar for a dog which I place around baby's neck ("Awww, isn't she cute?"). The basic theory of the bark collar is quite simple. When the dog barks, the collar zaps the dog with an electric shock. If the dog barks again, the collar increases the strength of the electric shock. This process is repeated until the dog stops barking, or is killed. My Cry Collar would do the exact same thing. Baby cries, baby gets zapped. I have never met a dog stupid enough to continue barking long enough to reach a lethal dose of electricity. Let's see if we can say the same for a baby.
Now some of you might complain that my idea isn't PC enough for the 21st Century. But that's just because you don't love your baby enough to teach it some self control over its crying. I mean, I got zapped with electricity all the time as a kid (I deserved it though... I just didn't know when to stop....) and I turned out just great!