Or maybe they just pushed Oblivion too fast out the door and their idea bucket had run low and didn't have enough time to put in what they originally had in mind.
Seeing as how they've had (... What is it? 6 years?) to work on it I hope that they got their inspiration back and hopefully they will have worked on the game mechanics a lot more.
This is more than likely the reason.
There were so many things cut from Oblivion because they had to get it out the door by the time 2K wanted it out, and because of limitations on consoles concerning the game engine at the time. That's why Radiant A.I. is nowhere near as good as it originally was, there's no town of Sutch, there's only around 5 voice actors, no soft shadows, and everything feels sort of copy-pasted.
Hopefully there will be a bit more leniency towards their next Elder Scrolls game, and maybe then we'll have something to please all crowds.