Sociologists will surely have a reason as to why neoconverts stake more me-mine-onlymine claim to old practices. So I will dispense with that psychobabble. But there is similar aggressive attempt to reclaim yoga as one's own and for a sincere practitioner this can be disturbing. Simply because many of those who staking claim to yoga hardly practice it.
But that is their problem. Seriously. If there is a toss between arguing for or against yoga, or just practising it, what would the most sincere person do? Precisely. Same thing is happening with religions around the world and that can be a dangerous thing.
I have learnt -- and I actually felt a deep depression for a few years about this aspect of teaching it -- is that oftentimes a yoga practice can help the crook become more crooked. That is why in ancient India the custom of initiation was instituted (not to make money for the guru!) so the teacher knew which disciple had the spiritual stamina and integrity to be able to handle the strengths and powers that came with a strong, solid practice. Remember the line from Spiderman.. with great power comes great responsibility?
Here is what Swami Krishnananda, the disciple of my Sadguru Sivananda, has to say about this aspect of yoga:
Nothing can be so beneficial as yoga is, and nothing can be so terrific and frightening as yoga is. This is the irony of the whole matter. It is not easy for a person to feel in one's own heart that a concentration on a form, what that form may be, inward or outward, is capable of bestowing abundance of the riches of the world. Who does not wish to become a king, if that were predictable?
These difficulties will have to be faced one day or the other. In facing them, many have failed, have had a fall. With such a thud, they had to break their heads. They would have been better without yoga than with it. "
If you know what are some of the powers yoga is said to bestow you will know that why in the hands of the crook, it can be a dangerous thing:
The eight siddhis are anima (the ability to become small), mahima (the ability to become big), garima (become heavy), laghima (become light), prapti (obtain all), prakamya (do /achieve anything), isitva (lordship /control over all), vasitva (control over the elements).
If you know the story of tantric yogi Milerapa, his guru Marpa does not reveal to him the secrets of what he is seeking because he knows Milarepa was already super strong. (With his tantric powers Milarepa had sought to avenge his family's suffering by attacking those who had caused it). Marpa first humbles him completely, in several ways that can only seen as pure torture, before he initiates him to the ultimate secret. Nowadays, it is easier to get yourself initiated into anything with a bit of money! But those days the real guru knew that too much a good thing, if not monitored, could actually be a bad thing.