My guess is that throwaway's statement was hyperbole, and Bed Bath and Beyond isn't a literal example of an employer that requires a polygraph. Instead it was an exaggeration meant to show how common the practice is in his circles.
My guess would be. Some sys admin did something illegal (some sort of fraud or something). So management wanted changes to prevent that in the future. And the cover your ass move was "we'll use polygraphs on new people!".
Huh. I was a very senior 'sys admin' type for an enormous retailer for over a decade, and polygraphs never came up for me or anyone else there.
Any idea why bed bath and beyond is into such a thing?