I think childless people are less forgiving than fellow parents. We usually sympathize with someone whose child is being a monster but who is trying to deal with it and separate them from the clueless who seemingly don't even register their child's annoying behavior.
But even sympathy wears thin if the struggling parent fails to simply remove themselves from the situation. Even if it means leaving a full grocery cart in the aisle, you should notify the manager with apologies and leave the store!!!!!!!
Leaving a store/restaurant/event a few times will hammer the point home, believe me. Especially if it's a place the child wants to go. If you can't leave (church, for example) then when you do return home, life should be as unpleasant as possible (no games, TV, swimming, playing with friends, etc...for the rest of the day).
I unfortunately have quite a few friends who are the clueless parent type. They don't even notice their kids running rampant. It happens more than you think.
Of course you have the other problem and that's the overly protective parent, who sucks in their breath dramatically each time little Precious falls, causing the child to react by screaming and carrying on way out of proportion to the injury. This type usually turns into the clueless once the treacherous waters of toddlerhood have passed.
I am Gen X, but I wonder what the heck is wrong with many fellow parents of my generation. I think it's a liberal/conservative issue.
You ever been at the store and found your kids getting on your nerves. Just where you're tired and everything they do seems worse than it is? A few weeks ago we took out the baby and the four year old. The four year old snuck a decorated notebook into the cart with the one year old, so he pulled off two of the buttons. We put it with the groceries to buy it. The four year old is talking almost non-stop. Then, I hear screamed across the store, "MOMMY!!" It was amazing because it wasn't mine. This loud little girl and her siblings were into everything -- so it seemed. Suddenly I felt so much better -- as the four year old tried carrying away a box of soy milk, thinking it was real milk.
I heard a radio host a while back go on and on about how when HE had kids he would make sure they never misbehave. Then he got married and his wife became pregnant. My wife and I smiled at each other, knowing he would shortly get his education.