Kerr-cell type electronic shutters don't move at all. Capable of
fantastically fast speeds too.
With (slow) liquid crystal technology where it is today, i can't help but
wonder why we haven't seen any developments in that direction.

How about 'Because the light has to go THRU the device, and that itself
degrades the image. And it provides additional surfaces on which dust
collects. Digital SLR suffer from the need to keep the CCD clean of dust, so
imagine how a light-shutter would affect things, too!