It's not about fighting for a yard, it's about not running out as early as possible. Sorry, man, we often agree, but I just saw it many times today, and even my wife (a more casual fan) did, as well. He stood to gain a couple more than he got, many times without absorbing a hit. What about his moves? He made some great ones. Why not try for more? Doesn't a great back go for a bit more and see if he can best his opposition and take it to the house?
You're right, he's a very good RB. He could be great, and I'm lamenting that.