If you mean the swearing, I think it plays a big part in why the voice acting is so good in this game. Well, to a point. It can go overboard, but something about characters actually saying FUCK so often in a game like Far Cry 3 makes it more believable. I mean, if you were in that situation, wouldn't you be swearing your ass off? Instead of in Far Cry 1, where they practically say things like "GOLLY GEE THATS JUST DARN AWFUL" and quite literally say things like "your ass is grass" and "I'll fix your little red wagon!"
It can go too far, though. It's a fine line to tread, but one that needs treading in a game like that.