It's hard to tell if a kid is disinterested. Distracted, maybe. Exhausted, both mentally and physically, sure. Disinterested...not sure I buy that at all. All of the players work too hard to be disinterested during a game. Someone will need to explain the look of a disinterested player to me.
During one of the Brooklyn games, someone posted that Ace lacked leadership skills because he sat on the bench and was quiet when he should have been vocally encouraging the team. The camera was on him for about 4 seconds, and yet a poster was somehow able to determine Ace wasn't a leader because he sat quiet for FOUR seconds.
Trying to ascertain what a kid is thinking or feeling from the stands or watching on TV is difficult at best. The players, who I am defending here, are not robots. They'll run the gamut of emotions during games, but I don't buy disinterest at all.