It's unironically pretty sketchy if you're read the Wikipedia page for it.

I have to say the school really let the instructor down. An instructor should not have to fill 70 forms.

You went through the entire article, misunderstood the point (aka he's talking about people who are cramming information, not people who are using it to skip filler content and contemplate over the actual information like you do), and this misinterpretation is fair, it happens to all of us. Few people corrected you in the reply.

But a lot of people instead of reading the article, took the title of the article and your comment as what the article meant, thus fulfilling the entire thing his article mentioned. Speeding through information. Kinda hilarious.

This is just an assumption on my part, but I feel like he just wrote down a list of what he has followed down in the past. He didn't write down the "why" because he wrote it in context of his own experiences.

Like that systemd portion looks very icky, but when you have the disclaimer in context. You'd want to go to something with the least amount of attack surface. Systemd is a giant project, and a very useful one at that, and for context I am firm supporter of systemd, but I can see why he'd put that in the guide, since his disclaimer says the guide isn't really about usability but minimizing the attack surface.

In turn it got submitted to hackernews by someone who read their article, and unfortunately some people would treat it as gospel and turn off their brains, since as you mentioned there's no "Why?", but it makes sense to not include it if he didn't really write it for the masses but just to document something for himself and his friends/colleagues.

Author says in disclaimer This guide is focused purely on security and privacy, not performance, usability, or anything else. He's not wrong. Gentoo makes it easier to have compile flags while building your system. Say you want to disable pulseaudio support completely? You can get rid of it completely from anything that might link to it by setting it globally as a flag you want to avoid.

Sure the guide doesn't follow a threat model, but there's still some good advice in there. If someone follows the guide as dogmatic gospel, as a list of rules to follow at all cost, that's on them. If one is responsible for securing down their stack, maybe they should know better than following everything down to the bone as if it's some gospel.