Users aren't banned for merely scamming, but I banned him for the spam bumping (+ ban evasion), but it's not going to stop him from scamming. He'll just use another account. I agree feedback should be shown to non-registered users but people also should also be doing a lot of research on who they do business with and they certainly shouldn't be sending bitcoins to people they don't trust.
Thank you very much Moderator for your help.