Because the reason for adding them changes every few posts. Its at the point that the argue for will change any time there is any resistance at all. It was originally stated to be a boost for WoE. No it won't. Its a waste of time to go back in and recode the wings for something like that.
Wings weren't for Alchemists only either. Everyone wants to add in Alchemy specific items because they don't want to hunt for their own ingredients and then try to pawn off that its good for the server over all when it isn't. Why give more work to the already overworked GMs especially something as petty as this?
All the advantages listed aren't really advantages. I hunt items and sell them. That's all I do. I'd rather more NPC sellable items in wings than something like this like how the wings used to be.