It is very odd indeed. Never have I thought about this before, and I think ALOT.
And to clarify, the Vampires in TES games are dead, although, they still have blood coursing through their veins and a heartbeat, like any other living thing. Although, blood is the only thing keeping them alive, the ONLY thing they need. They are fueled on blood, although their actual bodies are cold, due to them being dead. Odd in a sense, but plausable.
But anyway, I believe it didn't cross the creators' minds. That's why they need people like Us to come up with these ideas.
