I just want to emphasize how one simple rule, not letting kids play extracurricular sports, causes a witness kid's social awkwardness.
Youth organized sports is SO good for kids. Not that they should be so tied up in all their time off from school that they have no free time. But just one sport is a great help to them socially. Middle school years (ages 11 to 13 or so), are an extremely awkward age...Especially transitioning from elementary to middle school. Guess what helps? Having played a sport with local kids. They will have been teammates with a great number of other kids from other schools, from each year they have been on a team. It widens their circle greatly. When they go to middle school, they not only know the people from their elementary schools but from every other school in town. Middle school becomes a fun place to reunite, not a daunting place where you don't know most kids.
Also, people have all sorts of different natural abilities. Often these abilities are in sports. What is a witness kid who is amazing at sports supposed to do? Totally deny their talents. Hopefully they are also great and passionate at something else, because they have no chance at all to develop athletic talent. So, thanks to the society for completely cutting off the potential of so many children who otherwise would have had a whole lot more self esteem as well as have improved their physical abilities. You know those nerdy people who walk strangely? Do you think they were on sports teams? Not usually. Sports helps kids work out the kinks.