If you must know, account sales is not prohibited in this forum, transfers of ownership of accounts can be done at anytime. However, just as almost everyone has noted, account sales puts everyone of us at risk if the buyer is a scammer.
While account sales is allowed here, I think there should be strict rules which ensures that every transaction that involves transfers of ownership of accounts should be done publicly so everyone becomes aware that the account has changed hands. Anyone who fails to abide by that rule should be banned.
This way, members of the forum will deal cautiously with the account so they will not likely become victims of trust.
Account sales still happen, but it's simply "under the radar", but from my perspective, they aren't as common as they used to be in the past. Although they're allowed, buying and selling Bitcointalk accounts on the forum is frowned upon and sellers quickly receive negative or neutral feedback. A quick look at Reddit and you'll find a few posts selling accounts, but they're over 5 years old; there are no recent mentions. This has led me to believe that it's not as common as it used to be, and that's for the better.