Mariota can't feel in his throwing hand, they don't trust him. He can't stay healthy and the other option is no better than a QB who can't feel the ball to throw it effectively. That tells you all you need to know. If Mariota is going to be a starting QB in this league he's going to need to take a pay cut so the team can get a solid b option.
Mariota is always going to miss a few games.