It's not unreasonable for Montreal fans to want to give Slafkosky more time.
I'm a big proponent of people learning in different ways. Sometimes it's the topic, sometimes it's the teacher.
There's a reason, for example, Jack Campbell looked like a potential starter after being traded to LA. The further he got from Dusty Imoo, the more his focus and confidence left.
Other times, teams have a "curriculum." LA often slow boils their players, so someone like Byfield looks questionable at first. Other teams, like Anaheim, know when to apropriately challenge a player like Carlsson.
I haven't watched enough of Slafkosky to form my own opinion, but anyone who has, good or bad, would best be flexible. He still has a long road ahead with the demands of a first overall pick.