I count myself very fortunate.
When starting out on the path of training to become a yoga teacher, I was lucky enough to have as my course teacher an inspiring and inspired wise woman who, I recognised from the outset, discriminated the wheat from the chaff in what constituted yoga and what did not, in no uncertain manner.
An important ingredient in yoga teacher training, since there can be a lot of nonsense gathered on the way.
Her take on the various styles, schools, fads of yoga bursting out of every fashionable trendy studio and movement school was this:
If you practice the Yamas and Niyamas - the Ten Comandments of yoga, if you will - then you are practising yoga. if you further actively encourage students to follow these in their own practice you are teaching yoga.
Fertile Foundations further Development
The Yamas and Niyamas are the very foundation of yoga training - self training that is. If we do not at some stage take control of these essential parts of ourselves and address them then we are no way ready or able to nominate ourselves as yogi(ni)s let alone teachers. For those unfamiliar with Patanjali's Yoga Sutra, in which these precepts of Yoga are codified, Yama are the ethical principles laid down to govern our behaviour in society and Niyama are the way that we govern ourselves and behaviour in our personal lives.
It would seem that some 'schools' of yoga and the styles they promote, let alone encourage into their Yoga Teacher training programs, lose sight of these basic foundations or at best give scant observance to them.
It is these foundational observances that constitute the ethical foundation in Yoga. Listen to Georg Feuerstein and his profound understanding of what yoga is.
I have been to classes where certain 'trained teachers' have encouraged students to go beyond the pain - or if not then told they are doing it wrong! A back bend becomes the rack of the Spanish Inquisition - and most would agree that these religious zealots' ethics had left their ethics to rot in the communal refuse dump outside town.
Some have little or no understanding of the principles and practice of Ahisma (non-violence) and translate yoga as another boot camp on the path to enlightenment.
The point is that some may agree wholeheartedly with these observances of experiences and others may have come across yoga teacher training them whose ways have encouraged and promoted such students to rise beyond and break free from limited mindset shackles wherein they have been held prisoner by the very use of some of these practices.
So it is never the case of throwing all yoga teacher training programs out with the proverbial bath water just because some become trendy, controversial or pay lip service to basics.