You don't know if that comment was malicious (I don't think so), it survived long because apparently not that many people share your opinion that it should be gone (really, it only takes a few downvotes and flags to kill) and the thread got flagged off the site because for the last half year or so all controversial threads are hammered as soon as they reach the front page.

So while your logic is sound, there is no reason to panic because the assumptions don't hold.