Human Stupidity
I am a professional planked. I've planked in trees, on top of monkey bars, and some other stuff.
It's intense.
Dude they probably don't have those anymore. They took out sand boxes, you won't find them in most schools now. Took out swings from a lot of school playgrounds as well.
Gotta make stuff so safe it's impossible for parents to sue the schools. They've probably been removing monkey bars too, since kids can fall off of them.