Quote:
If a Bard does it, they are making their party fight much faster, contributing to more overall damage. But they can get EXP chests at the same time too, making for even more exp yet. They are contributing to the battle, which is indirectly related to the essential part, but still related not the less, and still doing the bells and whistles part of abyssea.
You are absolutely correct a brd or whoever can do it and overall it would be more efficient. However that isn't the point of it all. The point is that a job is determined by what people want and what they are willing to pay to get for it. The keyer offers cruor to open boxes which in turn supplies the rest of the party with exp/light/whatever. It's not the most efficient way to open the boxes, but in the end it is a useful job that helps the group as a whole.