Ты mean the same people that had an animal for a world president? сказал(-а) people would've gotten past that problem ages ago. Elfen Lied is based off the modern world, not a Фэнтези one like dbz...
People are prejudice against anything they don't like. Civil War was cause by whites being prejudice to blacks and not giving them the freedom and respect they deserve.
World War II some stupid idiot who hated a religion and killed everyone who practiced it.
It's like that plus in the case of Elfen Lied it's because they'r scared of the power they posses. или they'r jealous that they have all these abilities and we don't.