The French had been racist against Cagots for so long that nobody knows why. The guy who posted about them claimed they probably sprung up from leper colonies, but Wikipedia is uncertain.
Some of the best bits of the article come from 19th century research into the phenomenon. But since it's 19th century science, it's hilariously awful:
The French early psychiatrist Jean-Étienne Dominique Esquirol wrote in his 1838 works that the Cagots were a subset of "idiot", and separate from "cretins".[69] By the middle of the 19th century,[4] previous pseudo-medical beliefs and beliefs of them being intellectually inferior[13] had waned and German doctors, by 1849, regarded them as “not without the ability to become useful members of society.”
Of course, people making the world a worse place to live recently started to identify with the now-extinct group:
In 2021 and 2022 anti-vaccination and anti-vaccine passport protestors in France started wearing the red goose's foot symbol that Cagots were forced to wear, and handed out cards explaining the discrimination against the Cagots.[101][102]


