I'm actually pretty sure there's not a lore reason at all. At least I don't know of any. Someone call Anonymoose!
There was that rumor that they're half Roe and some people took to saying that was why. But that's not even true. They're not half Roes. And even if they were, Roes have eyebrows.
I suspect the real reason is that they were based off of General Leo's amano art from FFVI, and in his original art depictions, he has no eyebrows.
It's incredibly silly, but I guess that's just how XIV rolls.
I'm kind of scared for them to give Highlanders eyebrows, because I don't know if they'd give us good eyebrows or not. The spray paint has never looked good to me, and my fear is that they would do worse than that.
