Our program numbers are so dynamic, that frequently a player will have to struggle one year just to make the team, while the next year he might only have to show up to start. In a situation like this, there are some who let up too much. If that happens, and the player will not make the adjustment, it is in everyones best interest to let him go.
"Sports does not build character, it reveals it" is really appropriate in this situation. Some kids just need to struggle to perform. I like to reward the kid who works hard even when he doesn't have to.
I would always prefer to keep a returning lettermen, but sometimes players make the decision for the coach.