Rant away. It has not happened to us as much with the labs but more so with Archie.
We visit Bass Pro a lot and I'm more weary of the parents who let their kids run up to a dog especially if the dog is not looking in that direction.
Had Bandit there one time and a 3ish year old boy came by with his parents. I asked the boy if he wanted to pet Bandit and Mom had a concerned look on her face. Now, Bandit was not a pup but loved kids. Since Mom looked concerned I had Bandit by my side, facing me and put my hand on his head/neck, petting and controlling his head. Mom looked relieved and let the boy pet him. Kudos to that Mom and to all the parents who have had their kids ask before approaching. Not as many approach Archie and it's a shame. I understand their concern but all they have to do is ask.