Running back Robert Turbin was not a superstar for the Seattle Seahawks. No team needs every player to be an All-Pro. Some of the players need to do the dirty work, and players such as Turbin do that. He stepped up when needed and made himself a fan favorite because of his effort.
The same might be happening with running back George Holani, too. In his rookie season last year, Holani had a good training camp, but didn't make the active roster. He was signed to the practice squad, but appeared in five games and had three carries.