Really they should just have flights for obnoxious and entitled folk and flights for reasonable folk.
In general it is the person in charge of the annoying child who is the problem.
As comradejing said, most reasonable people do their very best to keep a child entertained and quiet on a flight.
That same person would most likely be considerate to other passengers if they were flying without their children.
The obnoxious folk just don't care if their kids are causing a rumpus, kicking seats, yelling etc. These same folk if travelling on their own will most likely be the seat recliners, the seat hoggers, the noisy eaters etc. Because they don't care about the impact on their fellow passengers.
So yes, two kinds of flights please.
The 'we're crammed in a tube arse to cheek breathing each others air for 8 hours so lets see if we can all be mindful and self contained and responsible and try and make it a tolerable experience' flyers
And the 'it's my arse, my cheek, my air and my tube. I paid money for this seat and the rest of you can just bog off' flyer.