"I'm a parent and I see kids waaaaaaay out of control in public."
I agree that kids are way out of control, but consider this: If you dare to discipline in public, there WILL be someone within ten square miles who will accuse you of child abuse and you could face not only jail, but losing your child to the wonderful "parent" STATE.
Of course good discipline from the cradle "usually" curbs bad public behavior, but not always. When I raised my kids, I could put them over my knee anywhere. Try that today and the consequences are horrifying.
I've always spanked mine in public if they demanded it. A few times of being embaressed and they never crossed the lines in public again.