One fault does not mean it's a bad idea. Also reading through it the largest issues I see it faced was that once people started enjoying it other people didn't like how they enjoyed it. Outdoor groups of people, gathering space, essentially using the public space in a public way, and other members of the public didn't like that, so going into it knowing what you want is key there.
However, like I said one failure 50 years ago does not mean we shelve the idea and never look back. We should look at successes and failures and determine what differences are.