Merit was made to determine one's post quality.
If someone buys and sells merit it means that he abuses the system.
I can guess that Merit trading is forbidden and those who try to trade Merit will probably get their thread to be deleted.
Merit also very helpful as it gives users the option to thank other users for their posts.
An ability that wasn't available before.
Yes, people are misleading the system and want to trade the merits to become higher level but they are not finding that they will be tagged with red trust. We have to be very careful with the merit system because we need to encourage a quality by supporting them with some merits.