How often in your life were you really threatened by crazy people or pitbulls?
As a kid that played without parental oversight we met every crazy person and every dog in town. This is still quite normal in the area I grew up in and I have never heard from anybody ever being seriously hurt by a dog or a crazy person in our area. Avoiding dangerous situations is something kids have to learn, and kids are not stupid. It is much more common that kids are too afraid than kids not having respect in the presence of a noticed danger.
That being said, many places in the US are downright kid-hostile, often because a failure to deal with social, economic, mental problems adequately or have good spacing concepts where people outside of cars count something.