The point of starting in prison is that you can have whatever backstory you want.
Except that at one point, for whatever reason, you ended up in prison.
Yeah, it's a blank slate, but in many ways too blank. I loved how Fallout 3 handled it, although that would be too specific for TES. It would be nice to at least define your background beyond the norm similar to the start-by-ship mod or many other games (including Daggerfall).
I think it would be great to have a race-specific quest-line but not as an origin, handled more like companion quests in Dragon Age or Mass Effect where they can be done more or less at any time and aren't revealed right up front.