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

Stores such as 7-Eleven that stock up on Karma Coins have exclusive rights obtained from Nexon to sell its virtual currency. You do not. That is the difference. The fact that both parties are getting something out of the transaction is commercial gain.

Also, you seem to have the mentality that 'if everything goes right, then it's not a problem'. By your logic, we wouldn't need drivers licences. If you don't crash or kill someone, what's the problem with not having a licence?

Again, this thread is not questioning the legality but the morality of the situation in the sense of level of reason. I never said the rule makes no sense. I said that banning for it being broken without being cautious or reasonable is wrong. There may hypothetically be some ridiculous law/provision in a suburb of say Nebraska which states that it is within a police officer's right to arrest you and throw you in jail for a day just for jaywalking with no cars in the near vicinity. That doesn't make some smart-ass cop actually doing that to someone an acceptable act. Does it?