Once again, I do not personally believe it is the responsibility of Sythe to babysit a newcomer who does not care enough about their money to explore and do some degree of trustworthiness fact finding. We do what we can, within reason, to create a safe trading environment. However, there comes a point when a buyer simply must have the will and initiative to show care with how they spend their money.
If the proposed scenario (listing sold accounts on thread without a link to the vouch) were some rampant issue that caused dozens of users to be scammed then I'd support. However, I can't think of one example where someone had accounts listed with fake sales that led to scams. Denisike, who you referenced, is not a good example for the scenario you're proposing. He actually did sell a huge amount of accounts. Your suggestion would not have prevented him from scamming people.