Good point -- electrics can fill the neigbourhood or be a silent practice buddy in a shared room.

In terms of technique, playing electric, amplified, might as well be a light year away from playing acoustic. But I have noticed that guitar players who move back and forth from electric to acoustic are considerably more versatile. An electric is exacting, with every note clearly defined; but with an acoustic, you create your own harmonics as a player, manipulating that magnificent living thing made of wood, and you cannot hide behind volume and signal processing.