Plenty of MMO's have no trading between characters, no mail system. It seems this is where they could start to freeze out RMT. If there is no way for an account to transfer gil to another account, then there is no need for RMT. Also, maybe doing away with all the gil sinks in the game would decrease the need for gil at early levels (i.e. no cost for using transport and things like that); then you only really need gil to purchase from the MB, which you really only need to do if you are in late game or an avid DoH player.

If getting rid of transfers between player accounts is the price to pay for no more RMT, then I say do it.