There are not any *actual* victims of people selling forum accounts.
Yes, there are.
The existence of a market for accounts makes "hacking" accounts profitable.
Therefore, a certain percentage of the people whose accounts have been "hacked" are victims of people selling forum accounts.
I dont think selling accounts makes hacking accounts profitable. If you were to hack my account, and it was not possible to sell my account, you could scam someone with my account
Your argument seems to be "there are other ways to make money from a hacked account, not only selling it".
I can agree to that, but it doesn't really counter my point.
That's basically the same as saying "there are other ways to make money from shooting people, not only contract killing"...

I disagree. I view your argument to be that the sale of accounts makes hacking accounts profitable, and is therefore the reason accounts are hacked. My counter is that hacking of accounts would still be profitable if the sale of accounts was somehow prohibited.
The existence of a market for accounts makes "hacking" accounts profitable.
There are other ways to profit from hacking an account other than to sell it.