I think that's a bit harsh. He does his best work outside, there is no doubt, but he's capable of winning the contested ball too.
What I think makes him such a good player is that he is a great height, can play tall and small, is quick, versatile and has a damaging foot. He has all the tools, and over the past few years as showcased the whole lot.
I'd really like to see him play predominately off a wing as I think he's a guy whose hands you want the ball in as often as possible, and with his size, he just makes for a difficult match up as he can drift forward, snare a mark and kick a goal.