I remember growing up, kids were taught by grownups (like the nuns teaching in my school) that you should say “Jewish person” instead of “Jew” and “Jewish people” instead of “Jews.” Except that it was all right to say “Hitler persecuted the Jews” but you couldn’t say the folks next door were “Jews”, they were “Jewish people.”
Likewise, when I took French in high school, the teacher said we shouldn’t say juif, we should use the euphemism isréalite.
The nuns told us this back in the 1960s when I was a young kid. How did this taboo on monosyllables get started? Is it still in effect? Nowdays I don’t notice anyone keeping up this particular taboo.