Seriously it's not because there was couple of news regarding this that it automatically become a fact. Lot of RMTs are just normal people like you and me. They farm gold sell it back to a website for cheap and in huge quantity. RMT slaves is more a myth than anything, people being forced to play etc. sure it does happen, but what doesn't happen in a country with 1.4 billion people?
It's just not the majority. Also people tends to forget that a lot of JP players and westerners are farming/selling gold as well. It's not only Chinese players. It can be very profitable even for people living in countries where life is expensive. Many skilled programmers use their own cheats/bots to get a huge amount of money and these aren't always the random Chinese farmer with no programming skills...
Using your own tool often guaranteed that it will remain undetected for a while.
I've got Chinese friends on XIV and it's annoying to often see people /pointing chinese people out and automatically consider them as RMT...