I suspect that some people are irked because nobody buys their trades on the spot. That has to be this "instant gratitude" folks who came into this game and expect their trades to be instantly filled. Unfortunately for all your kiddies who were brought up on "awards for participation" Trade Office and trade chat is not filled by npc's.
We are real people and if there is no need for stuff you offer than go cry to your mom. Or lower your price perhaps. But don't kill a line or two of either funnies or courtesies in trade chat. Quite few of us in this game know each other well and sometimes we "shake a line" in trade just because we like to, but don't feel the need to go and brag in whispers.
Besides, I found trade chat often quite entertaining with so many cool players typing a funny line or two in between offers. Of course trolls are there too, but I think the mods are doing pretty good job on keeping things in check. Anyway, that's my 2 cents.