First off, let me say that I think the title of this article was purely intended for "shock" value - and probably for a little self-promotion. The writer has a book coming out next month on the science of yoga - risks and rewards.
To be sure, there are some yoga classes that are truly not suitable for every body. And, yes, there are some teachers who may be encouraging/urging students to go beyond their current capabilities. With that in mind, the student must be diligent about her own safety. Many poses pose danger for someone not in the best condition - or someone with an injury or other limitation. In my yoga classes, safety is paramount to any posture we do. I talk "safety" throughout the class. "No pain...no pain". "Only go as far as comfortable for you today." "Listen to your body." Unfortunately, we, as a society, put so much emphasis on comparing ourselves to the next guy, winning at all costs, pushing the envelope, etc., that we potentially set ourselves up for failure...or in the case of yoga, a physical injury.
Ultimately, in my view, it is the student's responsibility to tune in to her body - recognize where you are, become aware of what you can do, pay attention and notice what's happening. And, then begin the search for the teacher who recognizes that in you and works with you in that honoring process.
Here's a link to the article in question: http://www.nytimes.com/2012/01/08/magazine/how-yoga-can-wreck-your-body.html?pagewanted=all