There is one thing that makes the "Treasure Hunter" ability truly unique among job traits and abilities in the game. It plays on the weakness that we are all inherently greedy. It should be obvious that within the game TH's power appears to influences crystal drops, and likely nothing more. But since TH is a trait and is "always on" so to speak, there's not any penalty to not use it. In many ways, TH gives people the will to go out and obtain specific drops by offering a hope that you've increased things in your favor.