I agree about the public behavior part, but childless couples need to also realize that everything can not be planned to the letter with children. Children puke, children throw, children do all sorts of things to thier parents' embarressment that they did not intend. Please remember that in many cases, it's not that people haven't taught thier children good behavior, but that children are still learning self control and won't always adhere to those rules ie they are being children. Try and remember, you were a child once too.
I think childless couples should stop griping about things like time off and stuff too. Let's face it, for your inconveniences now, it will be those same children who will be "inconvenienced" by funding your care when you are elderly so it all equals out in the end.
Typically, I am more amused with rambunctious children in public than I am annoyed. Lord knows it can't be easy keeping them under control. My beef is with the parents who are clearly not concerned with the behavior at all. And I agree about the griping: this is one of those, "to each his own" topics, in my opinion.