Although the song did start out as a "blatantly anti-Semitic song" a blood libel, it lost that attachment when it came to the US southern mountains where no one had ever seen a Jew. So, they did the next best thing and turned it into "The Gypsy's Daughter", thus enabling them to throw the burden of the ritual murder onto a group to which they had a tiny cultural exposure.
It's possible that what bothers Bennet Zurofsky is that someone who likes the song and story, trying to get the more "authentic" version, would uncover the old anti-Jewish or anti-Gypsy version and resurrect it (is that a mixed metaphor, somehow?).
Does a version of this story exist in Canterbury Tales?