Try rotating your hand without rotating your forearm and you'll quite clearly see where the rotation is coming from.
Even adding joints to wrists, elbows or shoulders still wouldnt get you anywhere near the realistic range of movement, as currently the legs are rather limited, when compared to their real life counteparts aswell.
As Parrot already pointed out, even adding just one joint would make the game tons more complicated. Thus I think it would be best implementd as optional in the rules or something that can be modded in.
Though I personally would rather see them ditch the whole clumsy four state joint system for something new and more eleqant(maybe something like in minibash, but in 3D and lot more fleshed out).
So I quess the question to ask here is:
Will there be a new control system for toris or will you stick close to the system we currently have?