If you're talking about printed circuit boards and the like, they can be ground up and the metals can be recoverd and reused. Even the fiberglass from FR4 boards can be recovered and reused. The problem is, most people are too lazy. When a TV, vcr, stereo receiver, microwave, etc. fails, they put it out for the garbage collector. As seen in another post here, the devices don't even have to fail for them to be discarded. It's often viewed as too much trouble to take it somewhere to be recycled, that is, if there is even a place to take it.
JB