Knowing a retainers name doesn't help the community it may help the Economy but you may want to talk to the crafter and get on good terms with them. Gives a reason to message somebody that way you can bargain a price, make a new friend, try and purchase an + item so they can avoid tax. All of those things make interaction between players happen or at the very least give the possibility to do so and that helps build the community. There was many times on FFXI where I had went straight to the seller/crafter for materials and negotiated to get a better price or an exchange of craft services and that was always awesome feeling to me and gave a feeling and sense of accomplishment like I had just made successful business deal.
I see your point and I take note but my point is that it would help with community building and there is not any if, and or but to it.
