Because that would get in the way of your hands which would be worse (unless it was an active robotic solution or a person moving it around all the time). It is much easier to just step over/around the wire than dealing with it in the air. They made it sound more of a problem than I have seen it to be in practice, though yes this varies fro person to person also be skeptical about anything technical that the GB guys say.
The Lab is awesome though. And once more, seeing anything on screen does not give you any idea how it is actually to be inside the environment.