Because there is no entrance charge, people will take their children because it's a form of "free entertainment" for them (the adults, not the children), while it may be an actual "business" trip for other adults.

Why would you take children to such an event? Other than to relieve YOUR boredom - there is nothing there for children who have small attention spans and nothing to do - a recipe for disaster IMHO.

Take them to the park. Play a game with them - why take them somewhere that holds no interest for them and is not geared towards them.

Signature line > "You can't fix stupid"