Question: Why change it at all?
I would not mind a bit more information about this.
However, I can think of two possible reasons:
1. To stop the sale of an item that originally may have been intended only acquired by quests, or by camping an NPC. I can hardly understand that this has been a major problem, justifying the introduction of a new moneysink.
2. To lower the threshold of the pocket boss tradeskilling world a notch.
In both cases, I assume that FC still wants the player to pay a little for it. 1 hour gametime in Jobe Scientists Quest (http://www.ao-universe.com/main.php?...&link=2&id=270) if you are newbie or low on creds, alternatively 10-15m for a player who is actively working with pocket boss tradeskilling, both seem like a reasonable price for me, considering that PBs make a significant income for many players, myself included.
Given that there is a mechanism in the game that computes a mathematical relationship between retail price and resale price in shops, it will be pretty obvious, at least in my little world, that it will be absolutely necessary to make the item nodrop. If I am not mistaken, this very mechanism has caused problems before, hence FC's attempt to avoid something similar in this case.
The chance that froob tradeskillers accidentally had the item on the wrong toon was probably fairly minimal. This should be possible to correct through a petition.