Syag, I agree – he is saying that others are saying so and he is responding. I find an interesting nekudah in his explanation: some people are looking for an excuse to not deal with the problem, and saying AA is not kosher is just an easy way for them to deny … In other places, he makes a point relevant to many entrenched positions here, whether on politics or anything else: the smarter the person is, the easier it is for him to convince himself in the correctness of his ways despite all the evidence to the contrary. The smart person can always explain the facts away.
Back to yoga, I don’t know enough to know how much “non-denominational” value is there. I just feel there is no urgent need to consider kashering it, other than keeping up with the Joneses/Cohens. you can walk, bike, swim, do calisthenics, I never heard of diseases that yoga is the only way to deal with. I typed “yoga cure for” into google and first suggestion was “diabetes”, it is all about relaxation and mindfulness, something that a Jewish person could achieve within the Jewish tradition. Without eating sugary cakes, in this case.