There's a reason why most of the heads you see are grey.  The youngsters have moved on.  If the older folks were "to go" and you so thoughtfully put it, there'd be nobody left and no bills in the collection plate.  And I'm sure some of the older priests would love to "step aside" into well-earned retirement, but there's a gross lack of younger priests to take their place.  The "vocation crisis" is only going to get worse until the RCC begins ordaining men and women, both married and single.