Have you ever noticed that computers have approximately a million cables?
After several years of having the horrible mess of cables under the library computer desk collect dust, cat fur, cat vomit, and crumbs, I snapped and put in a cable tray. I didn't have anything to make a cable raceway out of, but it's good enough to have the 4(!) wall warts, the power strip, and around 30,000 of the cables up off the floor.
And this is a computer that takes as much advantage of USB as it can, and which uses a wireless network attachment to the rest of the house. My servers, on the other hand, just have 5 cables coming out of them; keyboard, mouse, video, network, and power, so of course they've had their cables roped up and out of the way for years now.