I voted yes. Just because accounts can be sold covertly, doesn't mean that nobody will get caught. It's best to make an example of the minority who overtly trade accounts in order to dissuade others from doing the same. So long as people are aware that accounts are being sold, regardless of the rules, they won't put too much stake in someone's reputation.
In fact, if there's a section in the rules that says it's against the rules to trade accounts, the more logical conclusion is that people have been doing it. If nobody was trading accounts, then there wouldn't be a need for a rule.