Shouldn't be disallowing account sales to happen in this forum something where all staff members directly would agree on? As it didn't happen yet, is that because of the fact that there is some sort of resistance within the staff, or are you guys still looking for a way to incorporate it in the right way? I might be wrong of course, but enforcing such policy shouldn't be that much of a difficulty.
You are wrong. The reason that account sales are not banned is that it is not possible to enforce.
Trading of accounts would just move outside the forum.
Edit: FAQ
Q: I saw a guy selling Bitcointalk accounts. Why is that allowed?
A: Since we can't effectively prevent these sales (proxies, TOR, sales in other forums), we don't because otherwise we would be giving the users a false sense of security.