SNK and Sociology: Eldians and Burakumin
While the Eldians can be compared to many marginalised ethnic groups, I find one of the most apt comparisons is with a Japanese one.
The Burakumin are a Japanese ethnic group who are racially no different from the majority of the Japanese populace, but have been oppressed since the Edo period because their class made their living from leather. Slaughtering animals is considered an unclean act in the Buddhist faith, so they were treated as tainted and widely reviled. Even today in a predominantly secular Japan, the prejudice lingers, and Burakumin face discrimination in employment and even intermarriage.
The way they are discriminated against on the grounds of a ‘sin’ they are perceived to have committed definitely calls the Eldians to mind. Even those Burakumin who do not practice their cultural values, which have now been normalised in Japan (like Titan-based imperialism in Marley), are discriminated against solely on the grounds of their heritage and ‘tainted blood’.
While the ‘crimes’ of the Burakumin seem trivial to a modern audience in comparison with the very real crimes of the Eldian Empire, try putting yourself in the sandals of a medieval Buddhist.
The way they saw it, the Burakumin were debasing themselves for profit, insulting the teachings of the Buddha which they piously lived by. In their eyes, the Burakumin made themselves less than human, and this was the basis of their oppression. In the Eldians’ case, they literally are something other than human.
The Burakumin are arguably the largest minority ethnic group in modern Japan - Isayama is sure to have heard of them. It’s definitely not meant to be a straight parallel, as more moral ambiguity is poured on the pyre with the Eldians’ titanshifting abilities, and indeed the predicament is largely meant to reflect the themes of the series more than any precise historical event - a subversion of Eren’s desire to “kill every last Titan” and such. However, I would not be surprised if he drew inspiration for their situation from the Burakumin.