It's pretty clearly the curation. Parks have familiar facilities, guidance and support, and, frankly, advertising.

A friend of mine contacted me after a very bad trip to the Desolation Wilderness. She was shocked that the trails weren't marked, that there wasn't water etc. She thought it would be like a city park! Listening to her story I realized she didn't even understand in retrospect how close to dying she had been.

For someone like her a park is great: it gives her the support system she needs to enjoy the outdoors.