Yes, RMT is a huge Problem, but the only thing that actually can be done against them is punishing the ones who buy gil. Yes, you need gil, some people don't have the time to get a lot, but then it's to expect that you won't have nearly as much gil as other players who dedicate a lot of time and work to it. You can't expect to get everything for free.
I assume it's hard to find out who buys gil though, so you can't expect some sort of miracle task force to destroy all the RMT instantly. As long as no one is coming up with a solution (taking away new players rights to send tells or invites would just keep new players from playing, and RMT would just level their bots first) we will have to keep ignoring messages. Just saying "Get rid of RMT" won't do a thing.