Are Treasure Hunt rates too low?

[Phaethuer]

People can call me whatever they want, but it annoys me that I have done Treasure hunts every day since their release and have never once obtained one of the rare/treasure hunt only materials or minions. A fourth of the time I do not even get any items at all (other then the aetherial armor piece) and just receive gil. Try as I might to get these materials to craft gear or furnishings for my FC, they never come. Add to that my not wanting to pay 15k - 250k gil a piece for materials I should be able to obtain on my own, and I question if the loot rates for these items really has been set far too low or if the entire loot system for these coffers is flawed.
In previous MMOs, when it came to loot systems, many used a multiple category system for each boss/treasure chest. In these cases certain items were set in each category with the separate rates for the drops adding up to 50-100%. Example: in category one you have the the rare treasure hunt minion with a rate of 20% and the rare material with 30%, meaning there is still a 50% chance nothing from this category will drop. Then in category two you have 2 regular materials, both set to 40%.
This system would allow players that are actively doing these treasure hunts for the materials to not feel as though they have wasted their time obtaining the maps in the first place.
Yes I realize many people have had great success with treasure hunts, but for those that have gone the entire time without any success at all, it is highly frustrating.