I understand the benefit if we ever get there. I just don't think we ever get there. I think odds are slim we get there. As history has shown, only two guys who played an MLB game here six years ago are still in the organization.
I don't disagree with your conclusion regarding Grayson, but the bolded is a pointlessly narrow scope to use in searching for examples to support of either side of the roster decision. No reason to only consider guys who were on the cusp of the Orioles roster exactly six years ago. That's one team and one season out of 30 teams and maybe 30 seasons (I don't know when the current system began, I'm guessing after '94 strike) where these types of decisions can be made.
You don't even really need examples to be able to make a case either way. The plusses and minuses, and the likelihoods of each, are pretty easily understood.