Don't dismiss the entire community because of the loud people and their upvoters though. There are other people here, and they don't necessarily browse HN at a high enough frequency to outvote or outcomment the majority.
(I personally think the document is very good, on-point, and great advice for ambitious young people. I'm no longer that young any more, and I'm also aware of a different side: when you push really hard, you can end up burning out. That's the other side of the intensity the document advocates. You can burn out. It's the single biggest reason I don't push so hard these days.)