My parents were far, far from "parents of the year" but they understood that children should need not be in anyplace, anytime, anywhere. We did not take our first flight until we were pre teenagers and beyond the scream and shout stage.
Unfortunately, it seems that many want to have children today (usually for fashion sake) but are not willing to make sacrifices to raise them. As far as I am concern screaming babies have no place on a plane and children should be taught to keep quiet at all times. And before you point a finger, my mother (raising four boys) completely agrees with this opinion. Believe me, that is how we were expected to behave in the presence of other adults.