It is a judgement on the half-elves, by omission, because it's not saying "elves are bigots." Why do half-elves suffer discrimination? Because they're half-elves, that's why. If the reason why people don't like half-elves is because half-elf biology forces them to, say, eat the still-beating hearts of children to survive, then that's a useful thing to know. But "aren't liked by other people because those people are bigots" isn't a useful description. If half-elf hair was described as "not brown," that doesn't tell you what it is, just what it isn't.