Pretty lame for society to be so intolerant of children. Was everyone just born into adulthood complete with manners?? Smh.
Society isn't intolerant of children, society sees that there is a market for increased comfort in airlines, and that "peace and quiet" is an integral part of comfort.
They aren't charging more for children to fly.
Even if it did reduce the number of children on board, that's a worse solution than the problem currently is. Children learn by doing, including manners on planes. Remove a generation of children from anything and you'll have a generation that has no idea how to behave during that activity.