The only time I hear adults swear is when they're over come with anger and fustration, at or with someone, or when they get hurt or injured. I know other people swear all the time in common language, but usually those type of people are the kind that dropped out of highscool, and usually would be the first I'd kill if I were in the appocolypse. In videogames it rarely comes off as authentic, usually it feels like they put the fucks and shits in there to make the game seem more mature.
edit: I'm deciding to back away slowly from this thread, obviously cirtizism has no place in it. It's a good thing i mentioned the swearing thing before mentioning how the characters/artstyle look goofy and belong in the fun loving b-roll action uncharted universe not some dark gritty zombie game.