Work ethic, roles, and coachability make such a huge difference on the fringe players. If a player is a fringe sort, they better be able to play special teams, be a great faceoff player, work their ass off, be supremely coachable, etc in some combination in order to stick in the NHL. McLeod wouldn't be an AHL all star, but he fit a role when he broke into the NHL, was supremely coachable, worked his ass off, and was a good glue guy. Over time, he tried to add PKing to his responsibility to add a role to keep him up. For a face puncher, he is going to hit 700 NHL games and that is quite amazing.
Travis Morin is a fantastic AHL player... once of the best over the past decade. But he couldn't step into a NHL role because he isn't talented enough to be a top 6 guy, he can't be a PK guy, he can't crash and bang on a 4th line, he can't fight, he can't be a shutdown guy, he can't be a faceoff specialist, etc. He is a great professional hockey player, but he can't find a NHL role. I look at the same team and see Gemel Smith who isn't nearly the AHL hockey player that Morin is, but I see a guy with a better NHL shot. Smith can play a crash and bang game (despite being smaller), he can PK, he is supremely coachable, etc.
I know I have an unpopular opinion on Nantel, but these are a part of the red flags I saw. He couldn't carve out an AHL role, and he isn't talented enough to be a top end AHL guy. If he doesn't carve out a role this year, I don't think there is a lot of hope left there.
We will likely see something similar to what Bourne is alluding to with Ghetto here. Given a top 6 role with good players, he will produce... but he isn't good enough to be a top 6 guy on a good team. As the Avs get better (hopefully), he will likely fall into the fringes and not be able to stick with better teams in the NHL... but on bad teams he will probably be a 40+ point guy.