Users can delete their own posts, there were few users did that.
Oh, that’s true! I’ve run into this many times myself. It’s especially frustrating when actually useful posts get deleted. Sometimes I even give them merit just so I can find them later, but then when I check my sent merits, the post is gone and I can’t access the information I wanted.
So yes, that’s a real way to abuse the system. Although, if “carry” is counted at the moment of posting, then deleting posts would be pointless. In that case, the original proposal is definitely more effective than mine.
Also, with my merit/post ratio idea, nothing would prevent the trading of high-rank accounts. But in the original “carry” scheme, there are built-in barriers against that.