I don't know if it is as specific as that. I think it is just his personality. He is a really laid back, chill person. Lots of people like that have been captains, but they have had other leaders who are vocal, emotional and irrational (at times) to fill that gap. He has no one around him to bring that kind of additional leadership; this whole core is laid back and chill. JT faced the same issue.
Part of the problem we have is that our past successful teams have had a mix of leaders in the room. So when we look at Sundin, somewhat laid back, he had others around that filled that emotional leader role. Dougie and Wendel did that themselves and so on.
Until the core is changed, it will continue to be a tough job. Or, he finds a way to fill that gap himself and evolves with the situation.