I understand your point, however, there's plenty of systems to do things poorly too. Even beginners have a system for playing pool, it's just not the most effective one. As a matter of fact the game gets easier as you get to the higher levels of pool. What I do is much easier than what a beginner, intermediate or even advanced player does....the difference is my systems are slightly more "fine tuned" producing more positive results.
Many of my lessons start out with a "deprogramming period" where I explain and demonstrate why certain "common knowledge" is not effective. The most common topics are grip, and grip pressure - follow through length and speed - how to apply english - stance and why it's important to understand how the feet control BOTH sides of the body - aiming (consciously and subconsciously) - upper body angles and how to establish them consistently before you go down to shoot - why moving your back hand up and back changes your ability to control the cue ball - how to connect the shoulder, and the "chain reaction" of the arm/wrist/hand to the TIP - mental systems (taken from hypnosis, NLP, martial arts, zen, and other concepts and philosophies)
These categories of learning all have systems, and everyone must learn them in their own way. Rarely will someone learn these without the guidance of a mentor or professional teacher......in my day it was our "road partners" that wanted to win money betting on us that shared these powerful techniques. Now, that knowledge is diluted and opinionated. 'The Game is the Teacher'