This is the first time I'm seeing it. If resubmissions were forbidden I wouldn't have ever known of its existence. I'm not sure what the solution is, but I'd like to think removing it from my cognitive landscape for the sake of a forum host (a stranger) isn't it.
The past button, like you said, doesn't always work like that. And I know how to search. I'm wondering why there isn't a button when people always post comments to achieve the same thing a button could.
When something gets reposted, it's fairly common for somebody to comment with previous discussions. I hadn't seen this submission before either, but I'd also not seen the discussion OP linked.