I like articles like this, and I like this kind of discussion (even though I'm beyond tired of that NY Times piece). I'm wary of yoga teachers who proclaim specific health benefits of the asanas they're teaching, and I wish our community valued peer-reviewed, published, scientific research as highly as we seem to value anecdotal evidence. It's almost impossible to properly study the benefits of yoga practice—too many variables. We have to try it and see for ourselves what happens. But even though we may personally have experienced tremendous physical, mental, emotional and spiritual benefits, we don't need to stand before our students and give medical advice or make outrageous claims.
As for the "woo" stuff.... I love a yoga teacher who can talk about the spiritual tradition of yoga and yoga philosophy as it relates to their own personal experience. I love a teacher who has developed a deep, abiding interest in REALITY, who is transparent, humble and maintains a personal practice, who SEES their students and is genuinely interested in their well-being and progress, who is dedicated to the highest—I am intensely interested when a teacher like that speaks about spirituality in a yoga class, whether they are very green or very experienced. But when a yoga teacher chirps "Backbends open your heart chakra!" to the class, it feels like a set-up. Are we creating an expectation of a certain type of experience that may unintentionally block a direct engagement with what actually is in the present moment? Why can't THIS be enough? Why do we have to decorate and embellish our practice with flourishes and imaginings? What's so distasteful about WHAT IS, that we feel the need to constantly upgrade it?
Assumptions, projections, fantasies.... all obstacles on the path of yoga. If you have the opportunity to study the Gita or the Yoga Sutras, you'll find that both Krishna and Patanjali are constantly asking us to look deeper into what is already present here and now. There's no scarcity of wonderfulness, of sacredness, of sweetness or brilliance in the ordinary, the mundane, the simple.