The movie acknowledged unquestioningly that Captain America as a symbol is pure propaganda, but the point of the movie (and the character himself when written well) is that it isn't being a symbol or a soldier that makes Steve Rogers super, but being a good man who knows what is right, even when it can step on the toes of a few generals or politicians. The following quote sums it up:
"Doesn't matter what the press says. Doesn't matter what the politicians or the mobs say. Doesn't matter if the whole country decides that something wrong is something right. This nation was founded on one principle above all else: the requirement that we stand up for what we believe, no matter the odds or the consequences. When the mob and the press and the whole world tell you to move, your job is to plant yourself like a tree beside the river of truth, and tell the whole world — 'No, you move.'"