I disagree. I too have worked in these environments. As mentioned in the article, and in numerous other references about the Backrooms - the creepiness stems partially from the "liminal" feeling of walking around large, man-made spaces that are totally empty. Think walking around a shopping mall after hours. I had several odd jobs before I was in college where I had to work overnight shifts, sweeping the floors of large department stores. That feeling of "empty watchfullness" was definitely a thing, and it's captured well by a lot of the Backrooms content.

The other aspect of "creepiness" stems from the idea that the Backrooms represent an endless, malevolent labyrinth. One of the scarier aspects of being trapped in the Backrooms (for me) is that you would just wander around until you died for lack of water and food, in a bland corporate office corridor with fluorescent lights buzzing overhead.

I've worked in these environments too, and I think the modern "open" office without assigned desks give a far greater creepy "liminal" feeling that old suburban cube farms.

When you have assigned desks, people personalize their spaces. It feels lived in (at least a bit). A more contemporary open office feels more liminal, even when it's full of people. And after hours it's even worse: there's no trace of human habitation.