It is a position where very few guys last more than 3-4 years in the league. You almost have to find a RB every year to add to the roster that can contribute as a runner. This is even more true for Green Bay, because you damn well know Ted ain't spending money on any RB equivalent to the top 10-15 at the position or bringing in a free agent...so we will ALWAYS be rotating guys there.
Ted's drafted 2 guys in the last 7 years who have been contributors to the running game. He hasn't brought in anything in free agency over that period either. As a former LB, Ted simply hates RBs even if they are being put on his team.