Interesting article, thanks for posting it.
Just for background - I've got two daughters who played sports, and I coached a number of youth sports (including bball), but, mostly I coached girls fast-pitch softball for 20 years, including 8 years of good high-school varsity.
I agree with much of what the article says, as far as both the competition with other sports options (in softball, the addition/expansion of girls' lacrosse at our high school created competition for both players and gym time. We also lost good players to other spring sports). I also agree that the specialization can create burn-out, bad vibes, and, I would add, parents for whom anything less than a "starring role" for their special princess is consider a failure, and not worth participating in. Add in work conflicts and social demands, and you have this bizarre situation where it is hard to get kids to participate, make practices, work really hard and focus for a full practice .. and, yet, if you don't do that, then the final product on the field is poor, and then kids and parents get discouraged. "oh, Janie can't make a lot of practices, has to come late or leave early, but, we want her to play, and star,.. oh, the team sucks, she's not having any fun, I don't think it's worth it". One of my favorite expressions about life is "Everybody wants to go to heaven, but, nobody wants to die". High school sports can be a lot like that - everybody wants to win and look good doing it, but, nobody wants to do the drudge work, and put in the time, to reach that goal.
You also have coaches who can mess things up. Not having sons, I can only speak for girls, both as a coach and as a father - but, the right coach can make the whole program work, and the wrong one can drive it into the ground. And, coaching girls can be tricky, knowing when to put on your "coach hat", and when to put on your "father/uncle hat". Girls are very sensitive to slights, both real and imaginary, and you have to strive for fairness. That doesn't mean everybody gets to play or take a turn, but it does mean don't have "coach's pets" , and communicate clearly. Avoid being manipulated by players and parents.
Often with scholastic teams, by contract, teachers get "first crack" at coaching teams. Particularly with freshman and JV teams, the teacher coaching may have little to no experience actually coaching a team, or dealing with teenage girls outside of the structure of the classroom - and, if a kid has an inept coach at the introductory level, then, they often don't stay with the sport. Also, athletic directors sometimes don't put a lot of time or thought into selecting coaches of "minor" sports. This may not happen much with flagship sports like football or boy's basketball, but, I've seen it happen with softball, even at the D3 college level.
I'll add two more things. Competition for time isn't limited to job conflicts and other sports options. The whole computer and technology explosion eats up huge, I mean, huge amounts of the hours of the day for this demographic. Playing the "old fart" card, in my day, it was TV (4 channels!), radio, record player, land-line telephone. If you wanted to "do something" with other kids, you did games or sports. Organized team sports were a natural outgrowth of the neighborhood pick-up game. Organized team sports are not the natural outgrowth of spending hours on end playing "Left 4 Dead" or "Call of Duty", or "Grand Theft Auto V" or whatever. Those are physically sedentary, internet anonymous, and soda and Doritos are often involved.
This is the second of my "two more things". This is not a physically active generation. They get less exercise, spend less time outdoors, and are relatively overweight. Basketball is a tremendously demanding sport, body-wise: speed, quickness, endurance, athleticism, vision, judgement, and lots of repetition of mechanics. Other sports are easier.
