I doubt they do mich different than you do with their OS.

People are more motivated by feelings than actual logic. The person you are responding to even states that Ubuntu “feels good to use”. That is some car advertisement level of feeling based reasoning.

Another thing is that people really hate it when things change. Especially a UI change. Every change in the Windows UI has been met with disgust. And if there is one thing different between linux distros, it’s where they place all the buttons, menus, etc. So people prefer to stay with the distro they know.

The RHEL 7 book from OP is most certainly still relevant. For example, my department at work has not managed to switch over to the brand new RHEL 8 machines just yet.

It was an aprils fools joke from the company. I found the authors website, where he showcases it as part of his portfolio: https://mauricevanberkel.nl/portfolio-tag/easytoys/ And it is documented here also: https://www.adformatie.nl/merkstrategie/1-aprilgrappen-van-merken-professioneler-dan-ooit

The peak linux experience.