I think the ideal sport for recreational exercise is tennis. It only requires 2 people, 2 racquets, a ball, and a court. The court is perhaps the biggest obstacle, but there are public tennis courts all over the place. And if you've got money, you can join a tennis club. (The article author mentioned squash, which is fine too, but I think tennis courts are much more prevalent than squash courts.)
Team sports like soccer are harder to organize for amateur adults, though there are leagues and pickup games.
In a sense, the article author turned exercise into a social sport, with monetary prizes. The details are different, but the essence is the same: competition between two people rather than solitary effort.