I've worked with the public enough to understand why people like this People are often idiots in public in general, and it's way worse when they let their kids run around like crazy. I completely agree people should get to eat in peace.
At the same time though, there are times when people should not be so judgmental, too. I once worked with a teenager with Autism, and the looks/comments we would get from people out in public were sometimes really rude. (And he wasn't misbehaving. When he did, we would always leave the store just as I would have with any child .)
Also, honestly, nothing was worse for me than when my infant cried on an airplane. Trust me, it was worse for me than you. But I am not going to apologize for bringing him, either- because when babies are very young, it's not so simple to just 'get a babysitter' like with bigger kids. We were going to another state, our son had to go with us, period. There were other empty seats on the plane, and yet someone sat next to us anyway. I wish he hadn't , but that was his choice.
Again, I have worked around obnoxious kids. I get what people are saying. At the same time though, I think there's a big difference between taking a child on a plane versus an expensive restaurant. A kid doesn't need a fancy steak, but sometimes, they do have to travel. That's just how it is. I guess airlines can set up adult only flights if they want, if people want to pay for that, more power to them I suppose.