Because the game ends, and thats that. you lost. here they want the opposing team to lay down and let the other side get more attempts at coming back. Its a feel good exercise that is idiotic.
Just end the game at 35 points and be done with it.
No, if one team is up 35-0 and the losing team scores, the other team can then score another touchdown.
Even in the NFL there is an unwritten rule that at some point a team stops running up the score. If a team is up by 42 points in the 4th quarter they keep it on the ground and stop throwing bombs or big pass plays. I've seen fights break out over it.
If it's considered bad form in the NFL, why not youth leagues?