I've noticed a trend in negative reviews of Captain America: The Winter Soldier (there are some): the critic tends to not like Captain America. They find the character boring or stodgy. He's not a grim and brooding figure filled with faults, he's a stand-up guy who is aspirational. Steve Rogers was exactly the kind of hero as a scrawny guy that he would be as a big guy - his most heroic moment in Captain America: The First Avenger is when he jumps on the grenade and that's before the Super Soldier Serum - and for some people that's a problem. Not for me, and thankfully not for Marvel.
The First Avenger writing team of Christopher Markus and Stephen McFeely are back with The Winter Soldier, and they like keeping Cap a Gary Cooper type, says Markus. Even though Cap is dealing with being a man out of time that doesn't make him a moper:
You just don’t want to make him a sad sack. No one wants to go to the movie where the guy is mourning his past all the time. But also he’s this incredibly adaptive human being - he can learn a strategy and plan a battle in five seconds. He’s not going to get bogged down in the past because he’s always absorbing the present and processing it. It’s not in his character to wallow. Plus, he’s a man from 1945 - he’s not going to admit he has problems!
He does have problems, although they're not based on self-doubt. And as screenwriters it would have been easy to make Cap tormented in the aftermath of The Avengers (something that worked for Tony Stark, but wouldn't for Steve Rogers).
McFeely: The temptation is to give him a dark night of the soul, have him tortured over whether he’s doing things right.
Marcus: “Should I become Dark Captain America?”
McFeely: But the world doesn’t change him, he changes the world. His A plot was ‘Do I belong here, is there a place in the world for me?’ He doesn’t doubt himself, he doubts where he’s woken up. To marry that character story with a political story that demands it - that’s where the conspiracy thriller comes in, making him not sure who to trust.
The conspiracy genre also have Markus and McFeely the room to test Cap without undercutting everything that makes him great. Markus says:
The conspiracy movie, when we locked into that, gave us structure that was helpful. You’re on the run until this point and then you turn and take the battle to them. Cap is the guy who knows he’s morally right, who knows he’s very strong, this isn’t a guy who is at a disadvantage very often. But you put that guy in a conspiracy matrix, you put that guy on the run with his back against the wall, now he’s vulnerable.
That vulnerability is never fully exposed, but Steve's friends know it's there. That, says Markus, is why having Black Widow in the movie is so much fun.
She’s the kind of person who will poke at him over a long period of time. It’s not ‘Let’s get together and have our one big talk,’ she’s constantly needling at the tough surface he has to try and find the guy underneath.