1. You haven't seen the film, nor the context. Ergo, you cannot possibly know that, end of story.
2. You don't watch many cop/action films do you? Because "happily married with kids" is decidedly NOT the norm in those.
3. No, it's Marvel's continuing canonizing of Cap, usually at the expense of other characters. I like Cap well enough, but this "Cap is the bestest best guy ever, he can never be wrong about anything," obsession that they have is just irritating. Especially when they drag down other heroes just to pump Cap up, I'm sick of it.