Crowding was driving park attendance up, not discouraging it

Evidence

So desperate were New York’s masses that they made the trip anyway—in steadily increasing numbers. (In 1921, attendance at the park was 3,100,000. In 1922, it topped 4,000,000.) Every year, the Rockefellers and Harrimans built more playing fields and campsites, and nonetheless every year the playing fields and campsites were so jammed that Palisades Park on weekends, for all its beautiful woods and landscaped drives, seemed as crowded as the city its visitors had come to it to escape. — Robert A. Caro, The Power Broker, 637