For better or worse HN is run to meet YC's objectives. YC does not appear to value engagement for the sake of engagement very highly. People can disagree with that, But it remains a fact.
Most of the reasons dang put forth as to why he killed those particular threads could be applied to almost every thread on this site - depending entirely on the opinion of whomever happens to be reading them at the time.
Granted, you're right - it's YC's sandbox and they get to set the rules. But reading dang's post I can't help but wonder whether he's confusing diversion for intellectual quality.
My opinion regarding what beliefs`dang holds is that the 'Idea Sunday' was consistently earning karma disproportionately to it's contribution to the quality of HN and that this was creating a genre of similar high reward high noise threads [e.g. Screenshot Saturday, Tweet Tuesday etc].
My guess is that he looked at the threads closely before pulling the plug, not only because his post implies it but because it was allowed to run for several weeks before he stepped in and moderated. By the time action was taken a fairly detailed picture of who was looking at and participating in the threads was available.
Is it the call I would have made? I don't know because I'm not charged with that, (though I did flag this thread because of its poor quality) and I haven't seen all the facts.
