I'm going to come down on the control your kids side of this. I'll give infants and kids up to about three, a pass in a situation where the parent can not get up and leave, but that's about it. In pretty much any other public place, such as a restaurant, show, store, or church, control them, or get up and get out. It's called being considerate.
In 30 years of raising children, I have never knowingly let them disturb another person for more than 30 seconds without getting up and leaving the building. Infants were calmed down or we went home. Toddlers were disciplined and calmed down or we went home. By the time they made it past the toddler age, they knew better. There were several instances where the order was changed to "to go," so the rest of the restaurant could eat in peace.
There are a lot of parents, who think little Johnny being a noisy little E36 M3 is funny and cute and pretty much ignore, or worse, encourage the child. There are a lot of parents who can't control their children, because they suck at parenting. I'm pretty sure that is the group pres589 is referencing. He could be one of the people in the world, that prefer fingernails on a chalkboard to a screaming kid. I get it, I can't stand screaming kids. I'd rather stab myself in the eye with a stick, than listen to a baby cry.
Being a parent doesn't give you a automatic pass in not disturbing the people around you. For every person that thinks children are cute, there is a person that thinks they are annoying little turd blossoms. Just be considerate.
By the same token, when a parent is obviously trying to control the monster that every infant has inside them, be considerate. Sometime that means sucking it up and just dealing with it.
Oh, and the parent with the bags of ear plugs and hard candy, that is brilliant.