Objectively, he was terrible, and I'm unsure how you can reasonably think otherwise. The team finished 21st and 24th in CF% during his two years. The penalty kill was the worst in the league under his direction. He almost ruined Holtby because he claimed to know goaltending better than the goalies or his goalie coach (who left because of him). He made professional hockey players change their stick curve or blade because he felt he knew what was best for all of them. His was obsessed with handedness and that obsession caused him to deploy poor line combinations. His handling of Orlov was so bad that Orlov's agent demanded a trade. He refused to take personal responsibility for anything and publicly blamed or called out his players, insinuating it wasn't his system that was the problem but that the players were too dumb or too bad to execute his brilliant game plans. He made the Erat trade worse by playing him on his off-wing (there's that damn handedness fetish again!) and then demoting him to the 4th line when he couldn't make the adjustment. He was a micromanager to the highest degree. Do I need to go on? Holy **** he was awful.
Although maybe you're right, maybe he just didn't get a fair shot (hint: he did). But, I guess we may never know if he's a good coach because in a league run rampant with also-rans and retread coaches, there's evidently no other organization that thinks he's worth giving another shot to.