I understand where you´re coming from.
Then again, this isn´t meant as a time capsule to show the f"uture generations", what Photoshop was about, nor is it aimed to be a professional piece of education. It´s aimed at people that are just looking for an easy way to bring their ideas or sketches to life, without having to crawl through hours of colour theory, the difference between CYMK and RGB and so on. If this was a complete course about everything, PS has to offer, then you´re right, my approach wouldn´t be good. But I guess a beginner or hobbyist will have something like a starting point with this and gain quick results within a short time.
Greetz!