SE won't implement a gathering profession to deal with monster-drop because the following:
1) It will hurt their profits from players hiring extra retainers to make combat retainers to gather such items.
2) Players who are stingy will play another alt to get combat retainers, which mean they will spend more time playing the game, which requires more sub times. They may even be able to sell boosters!
3) They already try to band-aid this scarcity of monster-drop income via the use of bi-colored gems, which are used to goad players doing FATEs, which playing the game, thus subscription payment.
