Setups such as in the article aren't the result of "nerd times" and spending hours configuring just for fashion. They grow slowly over the years out of necessity and annoyance with your current setup.
> it's an OS, a GUI, it's the basis for getting real work done.
The basis for "getting real work done" is workflow. There is no need to be 100% efficient to be productive, but some people, like probably the writer of the article, like to push it to the upper limits, because they might be extra sensitive to "mouse lag" or some other reason.
There is also the extra perk of consistency. Due to their nature, xfce, GNOME, KDE change and consequently break things. Setups like in the article hardly ever change, even after major upgrades.
Also, as the writer mentions, Thinkpad x200: one of the finest GNU laptops ever. Real keyboard, all Fn keys work. It at a point where if software is too heavy to run on it, it's simply not worth running at this time. Any potential software advantages do not outweigh the superior compatibility and haptic of the hardware.