I often agree with you when it comes to contrarians and self proclaimed "realists." However, and I hate to say it, I agree with the OP.
This team's biggest problem is between the ears. They rarely step up, and they rarely respond. Just look at how they did last year after Muzzin got injured. They blew a 3 goal lead and got shut out in an elimination game. I thought they might have finally gotten over the hurdle with the comeback in game 4, but nope.
Honest questions, and I hope I'm wrong on this, but has this core ever stepped up for anyone? I don't recall. I'd even go as far back as them losing a game where their rookie centerman scored 4 goals in his first NHL game. To be fair though, very few remain from that team.
I hope I'm wrong, and I'd love to eat bowlfulls of crow, but I won't believe this team has the mental fortitude to push through adversity until they actually show it. Atm I think they'll shrink away and blame the loss on their captain going down.