Here's the main issue:

People think the only way to combat RMT is to give "legal" alternatives, which would also get abused by RMT. What Square needs to do is make it harder for RMT to get in touch with players. Right now, we have zero customization for communications; we can't have tells filtered to friends only, we can't auto reject friend requests, etc. Let people filter who can send them tells and let people decide whether or not they want friend requests open. Those two methods of communication is what RMT uses a lot aside from shouts. Make those harder to go through and you made it harder for RMT to get through to people.