Oh my dear lord that's a horrifically bad idea...
:sick:
I think you're right. I fail to see what good it could add to the game, all it would do is potentially force me to play a race I don't want to play to get access to the one I do. I don't even like how some recent strategy games have forced the player to play the campaigns for each faction in a specific sequence instead of letting you play any campaign whenever you want, even though when it happens it's usually because each campaign is part of an on-going story and playing them out of sequence might mess up the continuity of the story, Skyrim would have no such logical reason to do this as playing the game over again with a different race would still be playing the same story, just using a different character.
The only thing I should have to unlock in an Elder Scrolls game is a locked chest or door.