I have a feeling some of these RMT guys are starting to get desperate.
While we notice little because they keep coming back with new characters constantly, SE is actually hitting them quite hard with their purges.
Not only their advertising bots and farming bots but also their bank characters and several suppliers are being taken down constantly forcing them to find new ways to fix their gilsupply.
Believe it or not, there's quite a demand and the RMT are starting to show clear signs of struggle.
While SE (nor any other MMO company regardless of what some people claim) won't be able to eradicate the problem completely, as long as they keep up FFXIV will become less and less attractive for RMT companies.