I think in order for a sport to have a positive impact on children, they need to feel good about participating in it. It maybe doesn't faze some children if they're picked last, but every child is different, right?
I think anything we can do to promote self-esteem, self-confidence and confidence in general in a child.... At the end of the sport, the activity or the recreational activity they undertake, they should feel better about themselves and not worse. Otherwise, it just defeats the purpose. There's a lot of study on this aspect and there are experts much smarter than I am on it, but a child ought to feel good after participating in physical activity; otherwise, we're failing and the process is failing.