To repost what I've stated about Dorion before:
-Traded away Zibanejad and a 2nd for Brassard
-Traded away a top 4 pick in 2019
-Cost the Sens another 1st from the Dadonov NYC
-Traded Stone and Duchene for bad returns
-Traded young Gustavsson for an old Cam Talbot
-Wasted draft picks on Hamonic, Stepan and Matt Murray
-Traded high 1sts for Debrincat and Chychrun, only for those two to not stay long term
-drafted Jarventie over Peterka
-a bunch of bad first round picks(Bowers, Boucher, Thomson, Bernard-Docker)
The ONLY GM I would consider worse than him is Mike Milbury, and that's only because Dorion's drafting was a mixed-bag as opposed to being completely awful like Milbury's.