Your Child is a reflection of your parenting skills
A restaurant owner posts a sign requiring children of all ages to behave and use their inside voice while with in the confines of his restaurant. My god its beautiful, but no he's a villain, how dare he tell parents how to be parents.
See that's where the problem lies, he's not telling parents how to be parents he's asking them to enforce a publicly acceptable level of behavior in their own children. If that means he's telling folks how to be parents, because their children do not in fact know how to behave under these guidelines, then personally I believe they have bigger problems then not being able to eat out.
My beloved and I have a plan for when we are filthy rich, to reward the parents of well behaved children we come across in public. Really our standards are fairly low, we don't expect children to be silent little shadows that are often joked about in the saying "children should be seen and not heard". I don't believe children should be silent, I believe they should understand the concept of appropriate behavior for the environment they are in. If they want to sit at the dinner table and carry on a conversation in a normal tone of voice, or hell sing the abc song over and over and over again, that's fine. I though should not have to hear them from three tables over. They should not feel the restaurant furniture is a jungle gym either. If this is the behavior that's allowed in their own home, well bully for them, just another lesson in appropriate behavior in appropriate environments.
When I was young and out side playing with my friends i was expected to hoop and holler and sound my barbaric yawp over the world. Appropriate behaviour for the environment. Hell safely closed away in my room I could be as loud as I wanted as long as it didn't disturb the rest of the family. In common areas of the house, or in public settings, or as a guest in other homes i was expected to maintain a normal volume to my voice and move at a normal pace. One did not run around willy nilly even silent as could be, it just wasn't done. Though I grew up in an age where you were as likely to get a spanking from your friends parents for mis behaviour as you were from your own, and it was often worse because it meant you had one waiting for you at home as well.
But hell what am I saying, we can't even use red ink on their school papers to correct their spelling, telling them to be quite in public might suppress their precious indigo creativity.