Maybe I am alone on this? On a youth roster with 12 or 13 kids, yes, you don't want to be the kid who never plays and you should look for another team. But, on a school roster with 18 to 35 kids, I fully realize that some are going to play and some are going to almost never play. It's up to the player to earn his playing time. But, I would never root for another player to fail to help my kid's chances at playing.
True story: On our HS team my son leaped over an upper classmen to take a starting position on varsity. And, to be candid, the other kid didn't help his chances with his play. Someone once asked me about it and I sincerely told them that I wished that the other kid had batted .600 with 15 homers - because that would only help the team win. And, if my son was still good enough to play, they would find spots for both of them. There's 9 batting slots in the lineup.
Again, school ball is different. You have to root for the team. It shouldn't be a "me" game. But, maybe I just have an old timer approach on it?
That being said - yes, as a parent, root for your kid and hope that he earns playing time and has success and fun. But, don't root or hope for a teammate to fail to help his chances at playing time. I can't be that guy.