Would it be morally fair of Nexon to ban buyers/sellers of NX? I think not.

should the police not morally arrest you for selling/buying illegal drugs would be a real life comparison to what buying and selling NX is. It does not matter if the transaction comes out okay. The both actions are already illegal to begin with, and authorities should be allowed to do their job correctly and morals should not be part of the equation. Its a rule that's in place. Profits do not matter in the situation, the rule has been broken and they have the right to enforce such rule.