(Mind you, this is not about someone who doesn't like children. That's an entirely different issue. I respect that people have their preferences.)
I went with Miss Dash to see the Mad Science show in downtown Rockville last night. The show was fun. Many science experiments were demonstrated to an enthusiastic crowd.
Number of Attending Children: Approximately 100
Number of Problem Children: 0 observed over the course of two hours
Number of Children Acting Like Adults: 0 observed over the course of two hours
That number of ZERO is the normal number. I've been to ten such Rockville shows over three years.
Likewise, I go to many children's nights. Again, very little out of the ordinary. Lots of kids acting like kids, but nobody really causing a ruckus.
This lends me to believe that any complaints against problem children are complaints against the problem children who gain the lion's share of the notice, and thus the lion share of stories. The vast majority of kids just don't register and are not memorable. Thus, you have a selection bias.
What's a problem child? That's up to the observer. On one plane ride, my daughter kicked the seat in front of her a lot. She was a problem child to the person in front of her. To everyone else in the plane, she was not a problem child. So, is my daughter a problem child? You see the difficulty in answering that question. The aggrieved person will talk long and hard about the terrible child, but the unaffected observers won't talk even remember her.