Like most things in that era, Walsh's issues had less to do with talent, and more to do with coaching.
He was a turnstyle in defense, but the same could be said for most halfbacks his size. Our defensive structure wasn't set up to give him the level of protection that a guy his size would need so he was exposed in that area with regularity. Similarly, in attack he showed no variety because we played with none. One out running, flat attacking lines, Burns and Kingston trying hard but offering little threat/variation. Our main threats were Flash or Jennings cracking defenses on their own or bombs (which Walsh specialized in) that most teams in the league weren't defending properly (something that changed in 2011).
Walsh was a flawed player, but Elliott was by some distance the worst coach we've had in recent memory. Bad coaches make players look worse than they are, so it makes sense that Walsh would have had a lot more potential than he showed here. Maybe not an ATG, but I think he could have steered us to a premiership in the right system.