You'll understand why this is the case when you think about how much detail is held in the movement of the hands. The fingers alone comprise three bones each, times five fingers, for a total of fifteen bones per hand. By comparison, the entire rest of the body can comprise as few as sixteen bones (depending on how it is boned).
When you consider that each hand covers something like one twentieth of the screen area covered by the rest of the body, the tendency to overlook these small and complicated structures can be more readily explained. Still, overlooking the position of the hands is a serious mistake.
The best of both worlds would be to make manipulating the fingers easy
enough that it could be done quickly, and with a minimum of bother.
This tutorial will show you how to do just that.
Dabble Tutorial (Zipped file of Dabble Tutorial)
Page 1: Abstracting finger
Page 2: Control Container
Page 3: Constraining the Thumb
Page 4: Inverse Kinematics
Page 5: Abstracting hand motion
Page 6: Wave control structure
Page 7: Constraining finger targets
Page 8: Binding fingers to targets
Page 9: Setting the preferred bend direction
Page 10: Animating the controls