When you break it down, it's arguable that guys like Larsson, Fayne, Greene deserve to get more tougher assignments, while guys like Salvador, Volchenkov, and Zidlicky have to be utilized differently and perhaps, protected in terms of who they go up against, how much ice time they are subjected to, what types of situations they are used in (PP/PK), and who they need to be paired with in a particular game or situation. How much of it is age or talent, or a combination of both, would take forever to really go into and analyze and even then you might not get a clear cut answer with confidence.
Maybe it's just me, but I think some fans seem to think that with a C on his jersey, Salvador would turn into another Scott Stevens before our very eyes or they simply remember what he did in the playoffs and expected that to be a new normal, despite saying everything to the contrary. Salvador really at this point talent wise is no more than a 3rd pairing defenseman who is being played at borderline 1st/2nd pairing minutes and seeing tough assignments.
Don't get me wrong, I'm really not at all thrilled that Salvador got a 3rd year. It's going to be a sunk cost and we'll probably have to carry it on the cap, unless Salvador can somehow push through seeing what would mostly be limited 3rd pairing minutes. It'll be interesting to see how Deboer and Salvador handle that.