I don't craft mines but it looks like the active 'wire' bits are not voxels like most other things in Minecraft, but instead are painted on 2d surfaces yea? Please elaborate!
There's also the fact that the wires transmit information only 15 tiles. It's possible to build repeaters though, but those repeaters have some lag and take up space.
The hardest part are the memory cells. A single bit, even in the optimal configuration, takes up 3x3x2 blocks.