People just look at Maurice's record and say he's mediocre, but look at those rosters he had and compare to other coaches that are considered great. Its not even comparable.
People talk about Quenneville since he's the most comparable contemporary, who I think is an amazing coach, but look at the rosters he had, they're littered with HHOFers (Pronger, MacInnis, Hull, Sakic, Forsberg, Roy, Kane, Toews, Keith, etc...) and then compare to Maurice pre-Panthers with the struggling Whalers/Canes, then the shitshow in Toronto, then back to a re-building Canes team. Winnipeg had a good roster, but nobody on the level of HHOF.
Now that he has an actual good roster and he goes back-to-back finals. And I can say Panthers success is a direct result of the team buying in fully with Maurice's coaching, playing essential playoff-style hockey from game 1. The team hasn't lost when leading to start in the third period for like two seasons now. That's incredible.
Is he a legendary coach? I don't know how you judge that. He could be coaching for another 10 years, he's not even that old. By the time he does retire, he'll likely be 1st in all-time games coached and 2nd in all-time wins. I think that's pretty good and HHOF worthy.