Carbon is so readily available for combining with other elements and it appears to be a fine source for lubricating the wheels of matter in the universe and being that its dull in color creates a sense of illusive reflection. It seems only logical that it is the element most likely to be the glue that holds the whole thing together, it may not be the most plentiful, but when you want to create an object in a vacuum. You start with a simple and yet elegant design to grease the skids.