It may not do anything in terms of story progression, but it can be great for character building - a chance to express how your character would react in that situation, even if it doesn't change the outcome.

It's also the only time we ever get to 'hear' our character actually speak instead of just pulling faces, and that's important. Sometimes it's not even about choice - there's one clear intended response and the others fall flat. (There's at least one moment I can think of where our response is a key part of the scene, and it just wouldn't play as well if all we do is smile and nod.)