First, that website is hella weird to navigate on mobile. Luckily, the "read more" button brought me to the correct page.
Second, I really feel the author is looking at yoga as an "exercise," as opposed to a "practice." Yes, yoga is good for strength and excellent for flexibility - but that's not the point.
Yoga has a different meaning for each individual. Okay, so maybe for some it purely is an exercise routine to work through. Great. But for others, that "imaginary energy" does have a meaning. Even for myself, imagining my breath moving through my body helps me stay focused and breathe a little deeper. It teaches you how to pause, accept what life has given you, and let it go.
No matter what, the important thing is to listen to your body. Personally, I find hand and headstands super uncomfortable, so I adjust my practice accordingly if I'm in a class. Just not feeling it today? Seriously, you can nap on your mat the entire class if you want to. Your instructor is only there for guidance.
I find Skwarecki's analysis dismissive and incomplete. Yes, there are DEFINITELY yogis who are all about this "pseudoscience." And you know what? That's okay. Psychological health is as important as physical health. If we're all on our own personal journey, why judge others for what brings them peace?