Now, I know that having it on all ghosts would defeat the purpose, but why have any other ghost shell when the ones with Guiding Light are the way to get XP? Meaning, don't get ghosts that don't have it because then they will be pointless.
A possible solution could be purchasing an item for bright dust that would allow a ghost to have this perk. That way we would still have to work to get the perk. Something to allow us to make the ghosts that don't have this perk useful again. Please?