I direct you to the post I made about this
here.
It details a number of restrictions that could be placed on free accounts besides the global "No trading period." restriction we have now. The suggestions I made would make gold farming via multiple free accounts impossible, while still allowing free accounts to trade. Go bump that post if you like what I wrote :P.
The problem isn't with crafted vs. bought/dropped items, it's that a person can make a free account, farm gold with it, and then trade it to his other accounts, thus giving the primary account a huge advantage.
But seriously, go check out the post I linked, haha.