If account sales are prohibited then there will be no special place to sell accounts in this forum. I also did not find a ban on buying and selling accounts.
It is not prohibited nor deserves a ban.
It is similar to playing soccer in your garden, your parents didn't explicitly prohibit you from playing but they might get the ball at any moment if they are afraid that you will break the window. Well, the bad news is that your parents are always afraid.
I think clear rules are needed, so parents can let their kids play the ball freely.
But parents wont want their innocent kids to kill each other while playing would they? They need to impose some restrictions or at least some sort of marking system in order to mark those who are potential scammers and since bitcointalk is the ground for signature spammers; shitposters and account farmers as well.
Those who buy/sell account do it for either of these purposes:
1. Scamming by hiding under the "Elder Rank" that the bought has. Gullible newbies often fall prey of them.
2. Shitposting to get paid from campaigns - the "who does not like free money" is the root cause of this forum garbage.