Very interesting. Not the intent of the article, but it shows the power of positive thinking, affirmations, visualization et al. Silencing the inner critic seems to be the common theme.
Another theory is that everyone is naturally a good shooter but they have all sorts of problems from lack of concentration to body twitching to uncalibrated vision. Fix any combination of these problems and you will have a good shooter.
Isn't this just a matter of perspective though? Anyone is a good X if you remove the things that prevent that person from being a good X.