This would be a case of "people doing things different don't know what they miss". Some kids (future violinists or pianists for instance) spend huge amount of their childhood training and training, but there's usually enough to enjoy and enough to learn to not fall into the article's problem.
Playing under supervision is not so different, as for any group of more than a few kids, the supervisor won't be there directing every minute thing the kid does. IMO the problem the article states is less a lack of freedom than the quality of what the child does. And I don't mean quality in some elitist sense, but just in how much the kid gets from what he is doing (i.e. building towers in lego or teasing the house cat is chalenging and satisfying)
Playing under supervision is not so different, as for any group of more than a few kids, the supervisor won't be there directing every minute thing the kid does. IMO the problem the article states is less a lack of freedom than the quality of what the child does. And I don't mean quality in some elitist sense, but just in how much the kid gets from what he is doing (i.e. building towers in lego or teasing the house cat is chalenging and satisfying)