This issue has been raised multiple times that it's pretty much considered a pointless topic at this point.
You do realize, just because of a certain feedback requirement, they're still going to use the same methods to scam people oblivious to the rules of the forum? A requirement will make it slightly harder and prolong the process, but judging by what I've seen on here and offsite they're already determined to the point of excessive.
People will still bypass these new implementations you and this other guy are suggesting, regardless of what it is or how intricate it is.
If you really want to look on the more in-depth side of this, go through the dispute archive and compare the amount of disputes of users who are new vs users who have been here for years or have 50-100+ feedback, you'll be surprised of the outcome.