When I saw "Clan Bank" I immediately thought it was items, like the transfer system.
I think they just want you to be secure about it and use the marketplace for mutual donation agreements, i.e. Stones for +3 Longsword. I'm sure you're suggesting its a use-at-your-own-risk system, but there's always instances of somebody getting in an argument, GTXting the clan, and messing up what they can on their way out. Forums, strat gear/gold/troops, voice chats, anything they can get their hands on.
I can sympathize with the mods who wouldn't want to deal with those kind of shenanigans, as individual trades on the market aren't too time consuming. But It would still be neat to have, even if only to make use of extra non-loomed gear taking up inventory space, or to issue uniforms and gear for new strategies if they wanted. Might as well leave the option open to drop looms in too, but with the full understanding that you'll probably never see them again.