It's a translation issue; Chinese has more than one first person pronoun (I), and stuff like, I, your Father, or, I, your Mother, is really the only way to translate it without rewriting the entire sentence to get the same vibe across.
Like the other guy said, when someone uses I, your father, they are essentially asserting dominance over whoever they're talking to. It's one of those pride things that these novels are always on about.
