So why do you go to yoga class?
What is the purpose of your yoga practice?
Over the years I have taught many different styles of yoga.
Decades ago Iyengar yoga (alignment orientated classes) or Ashtanga based classes were dominant so classes were usually based on one of these two styles. Many of us taught in this fashion or similar reflections of these presentations. (I personally was a big Iyengar fan)
Over the years popularity slowly sculpted new kinds of yoga to grow. Some people embraced it others stayed in what we would call traditional (although WTF is traditional anyway? sitting down and removing anything that distracts us from an absolute feeling of unity).
As time went by it seemed obvious that people were not coming to yoga to learn how to empty their minds and free themselves from the illusions and suffering in this world. They were coming for the perfect workout and a little relaxation.
So why do you come to yoga class? It is because you want to stay young have a great ass and a touch of spirituality.
While you sit on your ass at the end of class for 5 or 10 minutes learning true yoga remember that even if you don't find your true self, or transcend time and space to unify your soul with the source of life, you are probably sitting on a mighty fine ass at the time.
Perhaps you will be lucky enough to have a great teacher who gives you a workout that doesn't wear down your shoulders and lower back while encouraging you to shine a little!