I can only suppose that it originally had some sort of quality assurance sotware on it that required sharing for some reason. If there is nothing in the folders I would be inclined to drag the whole qcsuser directory to the trash can and see if it breaks anything. If there are no obvious ill-effects then you could move it to an external disk or write it to a CD (just in case). If you use Time Machine then you could just delete it as you already have a backup.
That directory is not part of a normal OS X install so I wouldn't envisage any problems.