My opinion is that Miller was the fall guy for everything Card Walker and Don Tatum did wrong in the years between Walt and Eisner. If I remember correctly, Miller was only CEO for something like one or two years before Eisner. Miller seemed to be one of the few in the company that was actually pushing for positive changes, but Walker, Tatum and a lot of other influential people kept up the mantra "what would Walt do?" There's nothing wrong with asking the question, the problem is that many of them answered by only looking to imitate Walt's past accomplishments, rather than be inspired by his looking toward future innovations.
Anyway, Miller himself was the father of the Disney Channel and Touchstone, gave the greenlight for Tron which was the first film to use CG for the majority of its effects, tried to get "Who Framed Roger Rabbitt?" made, produced the very first Disney Broadway show, and tried to get behind a young Tim Burton. But he inherited a leadership team who ultimately dragged him down. When Roy E. let the raiders in, suddenly those same people jumped on the bandwagon and scapegoated Miller for everything negative they themselves had contributed toward.