PS, voting me down won't make the article any more on-topic, and it doesn't matter anyway, I have oodles of this karma shit, and if I have to burn it pointing out the reddit-bait, so be it.
On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity.
I think this would fit under intellectual curiosity, but who's to judge.
This is very clearly one of those articles that people vote up because they like the message and it gets them fired up, rather than because they didn't know these things (unless of course they happen to reside under a rock).