I made a thread on this back in the time between 1.0 and 2.0 once. Lot of talking about how hard/easy it would be to do. Finally they answered a question on it in a live letter and said no for the following reasons.

1. It would cause clipping issues.

2. It would make it to hard for our characters to do complex task in detailed cutscenes.

Now as we know this game is full of clipping issues everywhere and our characters are about as lively as a rock in most cutscenes the "real" answer is: Their to lazy to even look into it or it's just not worth their time to care about.