Sorry, I couldn't finish reading because the entire article is in capitals.

What would happen if no "Referer:" HTTP header is sent and Javascript engine is absent or disabled

Answer: The text will be mostly all lowercase, along with some sentence case

Looks like it checks for the referrer in main.js and adds the uppercase text-transform if you come from HN:

  let host;
  if (document.referrer) { host = (new URL(document.referrer)).host; }
  if (host === "news.ycombinator.com" || host === "lobste.rs") {
    let style = document.createElement('style');
    // let transform = host === "lobste.rs" ? 
    style.textContent = `
      body { text-transform: uppercase; }
      pre, code { text-transform: none; }
    `;
    document.head.appendChild(style);
    console.log("HN readers clearly can't handle the typing habits of the average trans girl.");
    return;
  }

Sounds like the author got called out for not capitalizing the start of her sentences[1] and decided that, if HN readers want capital letters, they will get them.

[1] https://news.ycombinator.com/item?id=39027187

Which is funny because if you engage Reader Mode in the browser, everything becomes proper except sentences, which still start with lowercased letters for some reason. Names are still properly capitalized. It's truly bizarre

It's a less... dramatic... version of what happens when HN links to JWZ's blog.

Right? Who thinks that is acceptable in 2025?

Someone who is writing on their personal blog and doesn't give a damn what is "acceptable" to some rando on the Internet?

If you're publishing a public blog, by definition your audience is randos on the internet. Also, the author is posting in this thread.

it was acceptable in 2024? what year did it become unacceptable?

Since October 1995 and the publication of RFC 1855.

https://www.rfc-editor.org/rfc/rfc1855

Communication has not been merely a matter of personal habit — it follows commonly accepted standards for exchanging information within a group. Ignoring these conventions risks your message being unread, unheard, or misunderstood.

That said, it seems possible the author is intentionally addressing a specific subgroup that has agreed upon a different set of communication rules.

Status of this Memo: This memo does not specify an Internet standard of any kind. - MY FAVORITE kind of Memo :)

Unclear, but it looks to be somewhere around the year 1000.