Some crafting materials are intended to be rare to make the crafted item more valuable. They're not intended to be crafted for groups of players at one time.

Minions are always relevant. There are always players wanting to add them to their collections, just like you. Therefore there is value in keeping the drops rare.

Make use of world visit to shop for the materials you need. But I would say give up on Atrophied Atomos unless you're willing to spend the gil. The Corpulence has always been extremely rare even compared to other rare materials.