Problem isn't the job, it's the items. Potions/Ethers are too rare/expensive to be worthwhile. You'd also generate a massive gil sink that would discourage players to play the job.

Not to mention, the only real advantage to that job would be the MP recovery (Ethers ftw). However, MP regenerates naturally now, and there's too many ways to get it back already. Ethers would just be a waste of gil at this point.