I think I'd be cool with more online passes functioning like this. If you like the game you bought used, chip in $10 to get more game and behind the scenes stuff. If you don't see a reason to pay, the game won't force you into a purchase, and you're really not missing out on much.
As for why they feel the need to pace things out, I think the only excuse they have for that is wanting to make their limited content stretch out that much farther for day-one owners.