Skyrim does support their train of logic though. Vampires and falmer both only use frost & shock, are resistant to frost (in lore anyway), and are vulnerable to fire. This seems like more of a style thing, though. Fire is warmth and humanizes its wielder (ex: Eragon), while frost and shock are cold and indifferent (ex: White Witch & Lich King). Fire is only "evil", and thus suitable for an enemy character, when it turns into devil's fire, or dark fire (ex: Balrog).
Skyrim does support their train of logic though. Vampires and falmer both only use frost & shock, are resistant to frost (in lore anyway), and are vulnerable to fire. This seems like more of a style thing, though. Fire is warmth and humanizes its wielder (ex: Eragon), while frost and shock are cold and indifferent (ex: White Witch & Lich King). Fire is only "evil", and thus suitable for an enemy character, when it turns into devil's fire, or dark fire (ex: Balrog).