User blog comment:DazzlingEmerald/The Hyuga/Ōtsutsuki Bandwagons Are Coming..!/@comment-24384232-20141102005901

Well aside from the obvious ability to perceive chakra making any non-phantasm genjutsu worthless, another advantage is that the perceptions you are trying to fool on a byakugan user and in general most doujutsu users is that their visual perceptions are quite different. You exactly create a subtle illusion when you not only neglect but are unable to conceive of how they view the world. Genjutsu against a blind person for example will probably fail because they like a byakugan user can detect the discrepancy in their senses.