The whole concept of rookies vs vets, IMO, should simply come down to whether the rookie/young player has proven himself to be ready with his play and attitude. Starting trash vets doesn't have to mean they are better players, they don't have to perform better, don't have to make a playoff push. They don't have to prove anything except that they're willing to make an honest effort on behalf of the organization. If young players can't understand that they aren't being measured up against the vet, but being measured up against the standards that the coach/GM demand for their new vision of a future team, then that reflects on their attitude. I doubt an explanation would be too difficult to understand though, especially during transition years, and shouldn't cause some cloudy misunderstanding or conflict of message in young players' minds.
This doesn't equate to some blanket process for all young players, in fact it is entirely an individual approach based on the individual's development. If they're ready they move up and play. If they struggle they go back down. If at some point they become waiver eligible then the GM has to make a tough decision, but based on the young player's development, not the vet's level of play (we're not talking about a Hossa, Iginla, or similar guy still playing well, we're talking about fringe guys). It has nothing to do with how well the fringe vet performs. Obviously because of guaranteed contracts and cap rules, etc there will be tough calls for GMs, we all get that and that's a constant issue for all teams regardless of the state of their franchise. Sometimes decisions are made based on other reasons, but that happens all the time. Generally though, the above is how it should work. And NO, that doesn't mean tossing promising guys off to waivers for no good reason, despite what some smart guys around here want to be super smart about.