For once the airline does something about this problem leave your screaming kids at home.
I'll remind you of that when you are told to leave your screaming kids at home, and you get arrested for child endangerment and abandonment.
Where did I say leave the kids at home alone? If a person is that dumb they should have kids taken away from them. Long plane flights are stressful enough why do I have to endure screaming kids, or kids kicking my seat back behind me. I never flew on a plane until I was 8 years old believe me I was told how to act on a plane. I see some parents letting there kids run up and down the aisle that's really stupid. One reason I started building a mileage account to avoid this by upgrading to first class.
And you assume newborns and kids under 2 - 3 years of age know how to handle themselves on planes, let alone able to speak coherently on a flight; especially those who are with mothers who nurse.
Your never taking a flight until you were 8 years old perhaps shows the exercise of forethought your parents had to not showcase you during your worst behaviour.. ever think about that? Nor have you thought about the fact that some children's grandparents or great-grandparents may not be in good enough health to travel to meet them, so the children must go to them, with the elders being more than 2 - 3 days drive, but only a 2 - 3 hour flight. You don't know their story nor what may be causing them to have a problem, so you perhaps need ot also show some compassion and/or empathy towards their lives as well, instead of thinking just about yourself.
Finally, you may not like it, but there are a good set of laws that (luckily) disagree with you on what should happen; laws regarding breastfeeding mothers being one of them.
Food for thought for you to digest.