On the surface, this can appear to indicate a lack of deep teaching and/or exposure to the deeper aspects of their respective arts. Not really. Rather it is a focus on the possibilities inherent in and the eternal strength of the foundations. In my experience, each of my teachers has exposed me to possibilities beyond my grasp at the time, but still within grasp ultimately. At the same time they emphasized the very thing needed to reach these new heights was more focus on the basics.
Teaching of this type is a two-edged sword. On one hand, it makes it easier to relate to newer, less experienced students but at the same time possibly boring and not challenging to older long-term students. Negotiating is a skill for teacher and student alike. The teacher must challenge the older student with the depths of the basics all the while acknowledging the lack of limitations. And when appropriate, giving the student the next thing they need. At the same time, the student needs to forgo the flashy for the basic, to do the necessary work. Still, I am forced to admit to at times wishing my teachers would reveal secret invincible fighting skills or mind-altering pranayama exercises. Instead they gave me hours of simple Qigong and Zhan Zhuang (Taiji), and basic meditation and listening to Om (Kriya Yoga). With time I have been able to understand and appreciate the ultimate value of their intentions. And I am now eternally grateful to them for their teaching discipline. In a nut shell it's wax on/wax off.
I recently listened to a fitness podcast where the guy being interviewed was a strength and conditioning coach in the NBA. He told the story of how when he was first getting started he met Kobe Bryant and witnessed his morning training routine. He noted that he was flabbergasted that Bryant spent a large part of this precious time going over basic footwork and movement drills--the same things that are taught and reinforced to young kids and high school players. So naturally, one of his first questions was why did this guy, the best basketball player in the Universe, spend so much time going over basic drills. Kobe's answer was that constantly reinforcing the basics was exactly why he was the best player in the Universe.
Further to the point, it is my impression that in the internal arts--at least the ones I practice--this is where we find Gong Fu and enlightenment. It's not really all that difficult. It is right here in our midst. We are that. When you get down to it, it's really quite simple.