And furthermore, how exactly could a polygrapher justify his or her job, knowing quite well that they themselves could easily be "duped"? How could one live with ones self, knowing they may have put real criminals, moles, or miscreants into employment just by virtue of the fact that the  polygraph process does in fact NOT really work?

It makes no sense. If these people gave a squat about national security they'd resign their postions and go back to college to learn a legitimate profession...