I think overall the majority of people who are practicing it as a subject are following the right line. For the aberration, don't blame yoga or the whole community of yogis
B.K.S. IyengarA scientist sets out to conquer nature through knowledge - external nature, external knowledge. By these means he may split the atom and achieve external power. A yogi sets out to explore his own internal nature, to penetrate the atom (atma) of being. He does not gain dominion over wide lands and restless seas, but over his own recalcitrant flesh and febrile mind.
B.K.S. Iyengar