The comment in the article is in the context of rack mounting them which is a common thing to do with Mac minis. Having it on the bottom makes it hard to press as you can’t lift them up when they’re secured in a mount.
Hard rebooot is the only situation where you should be using the physical power button on a modern Mac. If you're installing Macs on a rack, presumably you can sudo shutdown -r.
The button on the bottom is trying to tell you that the system is built to be well behaved on stand by.
I am working on a solution to make it easier to hit the button from the front of a rack shelf, but the fact I have to mess with 3D printing just to hit a power button is silly.
Older Macs also had the power button on the back, which was also annoying, but at least a Mac that's secured to a shelf could have its power button pressed pretty easily.
The Mac mini _requires_ a mechanism to press up from the bottom in any permanent-ish install.