Read more carefully. I merely said that people mostly do it as a challenge or as a cargo cult, doubtfully because it is a useful skill (unless you happen to spend an extremely large amount of time writing, which likely only applies to a small percentage of those that get told to learn Dvorak).

When I first got a computer, in college, my father recommended I learn Dvorak instead of Qwerty for ergonomic reasons.

My keyboard was one of the typical 80's/90's beige color, so I took a black sharpie and wrote the Dvorak equivalent on each key. When I was typing, I focused on trying to remember which finger had to move where for each character. If I couldn't remember it for more than a second or two, then I could look at the keyboard.

It only took a couple of weeks to get the basics down, and it was several weeks after that that a friend pointed out I had worn off the sharpie for my most frequently used keys (I hadn't even noticed) and I was typing at a speed comparable to all the Qwerty keyboarders in the dorm.