This is a letter that guruji wrote to Yoga Journal in 1995:
I was disappointed to find that so many novice students have taken Ashtanga yoga and have turned it into a circus for their own fame and profit (Power Yoga, Jan/Feb 1995). The title "Power Yoga" itself degrades the depth, purpose and method of the system that I received from my guru, Sri. T. Krishnamacharya. Power is the property of God. It is not something to be collected for one's ego. Partial yoga methods out of line with their internal purpose can build up the "six enemies" (desire, anger, greed, illusion, infatuation and envy) around the heart. The full ashtanga system practiced with devotion leads to freedom within one's heart. The Yoga Sutra II.28 confirms this "Yogaanganusthanat asuddiksaye jnanadiptih avivekakhyateh", which means "practicing all the aspects of yoga destroys the impurities so that the light of knowledge and discrimination shines". It is unfortunate that students who have not yet matured in their own practice have changed the method and have cut out the essence of an ancient lineage to accommodate their own limitations.
The Ashtanga yoga system should never be confused with "power yoga" or any whimsical creation which goes against the tradition of the many types of yoga shastras (scriptures). It would be a shame to lose the precious jewel of liberation in the mud of ignorant body building.
-K. Pattabhi Jois, Ashtanga Yoga Research Institute, Mysore, South India
Enough said :) No commentary necessary.