It's a concept that has been tried in a few places in California, but in residential neighborhoods, not public parks. I hope it works out.

KnR

One comment to the article worried about how it will be stripped bare as in "tragedy of the commons". In my experience, I've noticed exactly the opposite: that if food is there for the taking, it either gets taken by the birds or falls to the ground and rots. I'm thinking of untended apple trees in Colorado, olive trees in California, pecans in Georgia, pears in Poland; lots of plants in lots of places, I've seen plenty of food left unharvested. I've never been to North Korea though, I imagine that an apple tree there would be quickly stripped and then the branches cut for firewood.

People that forage for their food are considered a little bit odd. Just take a look at the YouTube comments on this video:

I can see how this could happen.

Once upon a time when people were not living in "planned neighborhoods", almost everyone had nut trees, berries & fruit trees. My grandparents had black walnut trees, raspberries, blackberries, apple, pear, plum , peach. Neighbors traded apples for apricots, peaches for berries. Nothing was wasted.

Of course the squirrels & birds had first pick