I don't have any strong feelings on the topic. Good players will get their chances sooner or later. Sure, circumstances might mean their chances come later, but they will come. In those situations where a team ends up with 2 players at the same position who are clearly MLB talent, something will budge sooner or later. Sometimes the "budge" means that one of the players gets traded to a team where he will be a starter. Sometimes the "budge" means one of the player changes positions. The biggest example of that that I can think of is when A-Rod went to the Yankees so they had A-Rod and Jetter at SS, the result was that A-Rod moved to 3rd base. If players are that good that their talent is a complete waste at AAA, they can usually adjust to a different position.