I wonder why the cool feature of being able to use both hands simultaneously was removed? Right now there also is the discussion about the right-click-throw and the left-click-use, which may sometimes be confusing.

It "feels" especially a bit weird that there is a sword and a shield, that cannot be used together. Evey kid knows, that sword and shield belongs together. This loss of a feature I find quite a pity. I know it was a bit complicated to switch items. I think that might have been the reason for giving this particular feature up. However other games solved that problem in fixing the right click item while only the  left click item is switchable. That means, the right click slot stays stable, while you still can switch items from your inventory with mouse wheel for the left hand. Usually a shield, close combat weapon or things like lanterns/torchlights  would be put on that right-click slot. But everything else is also possible.  Throwing items could then be done by pressing a a keyboard button + right or left click (similar to how dropping items works currently).
That offers a lot more nice gameplay possibilities and makes the weird quick change thing obsolete, as it is not intuitive, eighter.  It even needs quite some "training" or experience.

All in all: that idea would bring back cool two hand feature without loosing the comfort of simple and easy item switching. Additionally the quite newbie-unfriendly quickswitch and left-click use/right-click throw control could become more intuitive.