I think when kids are younger, it is "cute" when they play sports. We're in if for the fun. Parents are more relaxed (in general) at games. There is a spirit of fun and enthusiasm. Take Micro-soccer. It's basically a bunch of toddlers running around and if they manage to kick the ball any distance at all, let alone in the net, we bust out with pride.
Then they get older. There's usually a good mix of kids. The super talented athletic kids, the mediocre kids, the flat-out NOT athletic kids, they are all put together and although the atmosphere is more competitive, they still manage to work together as a team and the parents cheer them on. Only one or two tend to be uber-competitive.
Then, they become tweens/teens. Sports become cutthroat. Parents get annoyed when the less-talented kids get put in. Because points get lost. Parents yell at the coach to keep the talented players playing, to heck with the feelings of the less-talented players. They want to WIN. Parents scream at refs. They throw their hands up and yell at their kids when they aren't being "aggressive" enough. They criticize. They insult. It's a pressure cooker of barely contained, hypertensive, seething, boiling competition. And one false move can result in the lid getting blown off. Literally.
When they're older teens, there aren't any "bad" players on the team. Because if you aren't super talented, you simply WON'T make the team. Play badly? You get cut. Because when you're older, fun time is over. You are in it to WIN, and everything else is just second-best. You think stage moms are bad? Try the parents of talented athletes. They can be downright poisonous.
It's like Life, right? When you're young, everything is fun and everyone is special. Then as you mature, things get darker, reality sets in, and the kid gloves come off. Sports are like this. Life is like this. Sometimes we wish we could turn the clock back. Lately I've been wishing I can turn the clock back.
If only we could...