He just doesn't do much with the ball in his hands. At least not consistently. Easy to tackle and has a nose for the safety of the sideline. Would it kill the guy to take one of those edge runs and try and look for a seam to cut upfield. It's like the sideline is beckoning to him - 'come here, where it's safe'. He just continues to dance outside and run out of bounds at the first sign of trouble.
I think McVay and the offense would be a little better served by letting Gurley carry more of the load and really try and establish a run game / grind the clock with a lead. Why Tavon is getting runs between the tackles is also a mystery. Has he ever had more than 3 or 4 yards on any of those plays?