Think about Deledio. Here is a guy who played in the mid in his first season and looked like a superstar. How many years playing off a half back and best you could say is he is a good player. Finally gets a run in the midfield and is a total gun.
Dusty is too easy to pick off sitting in a forward pocket. He doesn't have the engine or inclination to run both ways. I'm not sure which it is, because if you look at someone like Heppell, he can run all day. So its not impossible for a player to be super fit coming out of under 18s. They just get fitter the longer they play afl. The coach wants him to do all the defensive things. Personally, I would run him in bursts like maxfield and let him smash some teams until he gets the engine or inclination to run a match out.
The reason I blame dimma is because I think he is underutilised. Not every player is self motivated. Its the coaches role to get players up and about on a weekly basis.