There are several reasons someone might prefer to use websites that work without JS:
- The page will load noticeably faster (and likely be faster in a number of other ways).
- The semantics are more predictable (buttons, links, scrolling, text selection, find-in-page, etc. all behave the same as on other websites).
- The page will work in Tor Browser's "maximum security" setting.
- The page is more likely to work better in screen readers or with other less-commonly used web browsing tools.
- The page is more likely to work in older browser versions.
- It used to be that a JS-free page had lighter CPU usage, though newer CSS features and browser setTimeout/setInterval throttling have changed the balance somewhat.
- The page does not require running untrusted/proprietary code on your computer (the browser sandbox is a small comfort).
There's no reason to require JavaScript to render rich text especially when it's an article about CSS prowess.
Most webpages that function as simple documents can be built without JS. If you build webpages, you probably have an intuition for what kind of functionality necessitates JS. When a webpage requires that users enable JS, then, when it doesn't seem like it should need it, that's a signal of either developer laziness or nefarious behind-the-scenes activity (tracking, etc.).
After writing a long article, creating videos, images, and no doubt doing multiple rounds of edits... why should an author also have to ensure that their publication works without JS?
From what I can see, they're doing so codeblocks have proper highlighting but also can be copied & pasted. It's a reasonable choice.
They're not lazy. They even have long, accurate alt tag descriptions for all their images.
If I would guess, they have an inherent desire to see their work viewed in exactly the way it was intended, so they deliberately refuse progressive enhancement when it's a matter of reader choice. The visually impaired who have no choice are accommodated. Anti-JS readers are not.
JavaScript is an RCE vulnerability. Browsers literally execute it as "run this malicious code in a vm, then nuke the whole thing from the orbit".
I dislike JS, because I don't want to let random websites to run arbitrary code on my machine.
Most importantly, enabling JS makes it much easier to spy on users, so I automatically assume that the website tries to spy on my and feel attacked.
I agree it's not healthy, and I didn't care about privacy that much in the past. I guess this may be caused by my work experience.