Comment by dang

The mechanism is simple: people keep running across it and finding it interesting. It's not spam, it's just the statistical cloud at work.

On HN, reposts are fine when a story hasn't had a significant thread in a year or so (see https://news.ycombinator.com/newsfaq.html). So it's certainly ok after 5 years! Though I'd swear we'd seen more threads than that...