Why is it that a version of this that was posted half an hour before this was posted was killed, while this is allowed on the front page?
http://hnrankings.info/6950932,6950735/
No idea. I saw it, followed the link, and thought that while the item has some really, really bad points, it actually has some elements of truth, so I submitted it, and it survived.
It may well have been deleted by the submitter, or flagged to death - I don't know the circumstances of the demise of the previous submission. It's not clear why you talk about it being "allowed" on the front page.
<fx: shrug />
The foibles of HN - sometimes people don't join a discussion and find underlying truths, but prefer to flag it out-of-sight, out-of-mind.