I would have to disagree with that being the reason, because the only way flux gets into the game is by either someone donated, or did an offer, also the same with with FS. So even if we were allowed to do fsp/flux trading all its really doing is switching who is holding them, the amount of flux/fsps in the game actually never changes because the game doesn't have more put in or taken out.
There are a few huge reasons why not to allow it though...
I see some huge reasons too that I will not bring up for obvious reason....
but your above argument is flawed
#1 if someone already had a considerable amount of FS currency, right now it is locked in FS and they have to buy the new SS2 currency
#2 it is much easier to "recruit" a new player and help them reach level 100 in FS (earning you many free FSPs) than it is to "enlist" a new player and help them reach level 100 in SS2