3. OP entered the chatbox, and copy-pasted not only the referral name but also the scammer's bank account
4. The scammer sent the money to that bank account which was obviously his and took the coins too
That was naive. In the case Binance saw the money was sent to that bank account and released the coins to the scammer. There are no blaming to Binance.
Was he an established merchant (i.e. has lots of ratings)?
For Binance, the buyer is the victim and OP is the scammer. If they moderate the ratings then they will in fact chance the OPs rating not the buyers.