He was not. People sure do love twisting the words of those... I believe it was a whole 5 or 6 agents, who were likely just following media hype anyway.
Leaf fans shouldn't. The poll forum, which hates the Leafs, would.
He inherited a team that overachieved in one year on the backs of superstars on ELCs, great goaltending (most notably their backup acquired off waivers playing at Vezina-level), great health, great shootout luck, etc. All things Dubas has not had, and all that season really ended up doing was creating ridiculous expectations in the minds of some Leaf fans. Even still, our best year was with Dubas, and he's addressed weaknesses and raised the range of what this team is capable of significantly since taking over, despite some very difficult-to-maneuver situations.
Those are not his key trades and moves. You basically just cherry picked exclusively the ones you perceive as worst, and then misrepresented what actually happened. Moving Marleau was a necessity caused by his previous GM, and was the best possible option. Due to an unforeseen global pandemic stagnating the cap, after seeing more of what Kapanen and Johnsson could bring, and as new players stepped up to take their place, Kapanen and Johnsson were moved out. The return was very good, especially for Kapanen; likely the best trade of the offseason. The Kadri trade was not remotely close to "one of the worst in team history" (good lord LMAO), and while it didn't work out quite as planned, it was still a necessity to fill key roles, and Kadri's impact was fairly easily replaced. It ended up being quite important with all of the defensive injuries. We now have the original defenseman targeted in a Kadri trade (Brodie), and the better center (Kerfoot).