I think it was a conscious cost saving decision. Less animations to develop.
Animations are at least partially in place, actually. If you have nothing at all equipped in your right hand, clicking whichever button you have assigned to right-handed attacks will perform a blocking move instead.
So, you can still block with your right hand, but only bare-handed. Shields are right out.

As far as I can tell, that along with other maddening inconsistencies--like being http://cloud.steampowered.com/ugc/630730982034873860/7C8A48E3914A5DE51B175DCE37616D30839FED7D/ a one-handed weapon equipped in the left hand, slower attack speeds, no finishing moves, and let us not forget the epic fail that is the keybinding--is all part of Bethesda's continuing conspiracy to drive lefties like me up a wall and across the ceiling.
So far their plan seems to be working.
