Exactly! The shelf life of being a RB in today's NFL is not worth any kind of long-term investment. Even the greatest RBs who ever played had maybe, what , 3-4 years of playing at an elite/MVP level? The majority of a RB's career is about surviving to get over the 1,000 yard hump. Even the great Emmitt Smith was not all that special after the 1995 season.
Fans just get caught up in the moment and right now Bijon is the flavor of the season. In a few seasons, no Cowboys fan is going to still be wanting Bijon over Mazi Smith.