Soon they will learn how to sell merits without fear.
Soon? Those people are already selling merits 2 days after it was implemented.
Without fear? Well, if someone is selling merit, they're considered fearless. Because they are not afraid of the consequences once caught. It is actually still rampant in the community today and the staffs and mods are still active in catching these parasites.
Maybe he didn't able to saw into those people who trade or sell merits after the sudden change of the system. Yes, after that there are people who do already sell out merits because they do saw this is the main requirement for a certain account user to rank up and now its being abused but same as you said almost everyday you would able to spot out on meta section about selling merit or abuse complaints.
This wont be easily stopped since most of the merit abusers came from different local boards and its kinda difficult to spot an abuser specially when youre not familiar with the language. I know there were some people from different local boards who helps to catch every one of them. I'm also doing it, as long as I catch someone trading merits or selling, with the proper evidence, I would gladly present it in meta section.