I'm wondering. And I posted, after the Hawk's game, that I liked the fact that he seemed to be taking every inch rather than trying for the impossible. In that game, however, there was no place to 'bounce to'. SINCE THEN, however...
I have noticed the same thing, not always, but enough that I'm concerned. He does seem to run up the back of the blocker and continue that path much too often... rather than 'bounce', as you call it. While I maintain the opinion that he's running into a wall and there simply is no, or very rarely, daylight to be seen or bounce into he seems to be developing a habit of not looking... not reacting.
You seem to think it could be that he 'never had the ability', much anyway?... and this I doubt. He showed the ability last year, IMHO. Gurley seems to me to be the prototypical TB when FB's were used often. His 'talent', to me, seems to be the more angular designed run plays/blocking rather than the N/S routes the Ram's use almost exclusively. - JamesJM