a couple of points from a former child athlete with no experience or interest in coaching or ever watching a current child athlete.
1) the stuff michigan said about the adults caring more about winning than the children is complete bullshit. winning is the entire point. without trying to win, it's just exercise. might as well hop on a treadmill. sports are only fun when you try to win. you can still have tons of fun if you don't win, but you can't have hardly any fun if you don't try to win. there is nothing more boring than playing a team sport where score is not kept and/or both teams aren't vigorously attempting to win. i'm not a particularly competitive person, btw, and wasn't a competitive child.
2) the only thing more boring than playing a game where no one cares about winning is sitting on the sideline watching other children play and/or playing, but not being involved in the action. jesus christ, that sucks. eff that crap about the fat kid needs to learn to play on the line because he's good at it and sucks at everything else. he deserves to be a qb or rb or wr just like everyone else.
i don't know what the upshot of that is. maybe (definitely) don't play games where large numbers of children have to be linemen or some other position that sucks. and make more teams and have less subs so that everyone has to play and coaches aren't bitching about having to play the shitty kids and parents aren't bitching about their kid not playing and kids aren't stuck on the sideline watching other kids play. like structurally remove the ways in which children are forced to do crap that sucks and then let them play and compete and have fun trying to win and don't be stupid about it by trying to tell them that it doesn't matter who wins when the entire point of the activity is to attempt to win.