every gm makes mistakes. we look at the gms of Boston and Detroit as good examples but you have to look at the mistakes they have made to
Ex. Detroit - signs Weiss to 4.9 for 5 years while letting Filppula walk
Boston - trade Seguin to Dallas for Eriksson (now not a horrible trade but Seguin is the better player and is much younger)
everyone is quick to blast Gillis' bad trades but they never mention the good ones (Higgins for a 3rd).
He sure isn't perfect but he is better than most.