Availability bias? A major story about a chain of suicides of entrepreneurs on a Las Vegas tech hub was moved below the fold in spite of deserving the top position. And it quickly went to page 2 after that.

https://news.ycombinator.com/item?id=8404207

There were many HN stories promoting that place for a good while. But when things go sour HN looks the other way.

Dropbox problem story first moved below the fold, then deleted.

https://news.ycombinator.com/item?id=7568267

Those are just 2 examples. I'm not all day on the site, so I very likely miss most of these cases. This is just a tip of an iceberg.