Kreider is a long-time and career long Ranger. He's been a part of the most significant core this franchise had in probably a couple decades before it. He came into the league under Rick Nash, Dan Girardi, Marty St. Louis, Brian Boyle, Ryan Callahan, Marc Staal, Brad Richards, and obviously, Henrik Lundqvist. He's had three vastly different coaches, been to a Stanley Cup final and on several deep runs (with this franchise). He is reportedly respected and depended on by young prospects of any status in the organization. They signed him to a 6 year deal with move protection as a 29 year old. You don't do that because you expect a player to match or surpass that value on the ice, not exclusively at least, for the life of that deal.
It's not important, but to me it just seems obvious that Kreider is the only real candidate, other than maybe Mika (who's a pending UFA). To not give him the C--moreover in favor of Trouba--just feels disrespectful and misguided. What has Trouba accomplished in this league? More importantly, what has he done for this franchise and as a Ranger. I don't dislike Trouba, and I don't know him personally at all, but frankly the answer is not much.