I concur with the view that it's not so much the brats but the brat's parents that are to blame for this bad behaviour.

I fly to Singapore (via HKG) on a regular basis and I can't tell you how often I'm surrounded by car alarms when I'm in Y. When I'm in Y, I usually wind up in the bulkhead row, which is where a lot of the airlines move families with infants. Besides being the beneficiaries of a constructive upgrade, I'd say most of them are pretty good with their kids. But the 15% who are not make it a pain both for the back of C and the front of Y.

There was one time I was in C on NH and an entire family surrounded me. Mom, Dad and two boys. They proceeded to keep themselves occupied for the entire flight, not so much as uttering a peep. It's all about upbringing.