Waiting to register and pay, I heard a woman ask what Hatha yoga was, and the official answered, "Hatha is more of a classical style of yoga and tends to be slightly easier for beginners than some of the advanced styles."
I felt a little twinge of energy hearing this and had to let it go, breathe out, smile and walk away.
Since yoga came to the west, it has been taken further and further away from what it actually is. At least, as far as Hatha yoga is concerned. Hatha yoga you see, is the postural work, the physical, exercise part of yoga, the "asanas." There are myriad of different styles of Hatha yoga with the most popular styles pretty much all coming from the lineage of Krishnamacharya.
The styles that became popular in the west first were brought here by Krishnamacharya's students; Iyengar, Jois, Indra Devi and TKV Desikachar. Ashtanga vinyasa is the full term, now usually shortened to just Ashtanga. It differs from Iyengar because, instead of holding each posture, yogis "flow" through a pre-determined series of postures. Whereas, with Iyengar, postures can be held for up to 20 minutes.
Krishnamacharya had a certain reason for developing the style of Ashtanga vinyasa. His school was in a gymnasium in Mysore, India and he was teaching young boys about fitness. Because the boys were also studying wrestling and gymnastics, the fast, energetic flow of Ashtanga vinyasa suited them best. He developed the style to suit a certain physique.
But when he taught Indra Devi, Krishnamacharya used a completely different style of Hatha yoga. Devi had to push Krishnamacharya to teach her Hatha yoga, he wasn't willing to teach her at all but, when he finally did, he taught a style specifically for her.
This is the classical guru/student connection. The student asks to be taught yoga and it is up to the guru whether the student is worthy or, not. The guru might not even start with yogasana. The student may first be taught mantra or pranayama, or meditation, depending on the abilities of each individual.
I would hazard a guess that a large percentage of people that have a regular Hatha yoga practice, might well not be allowed anywhere near yogasana if they were studying with a guru in the classical sense!
The different styles all born from Krishnamacharya's modern Hatha yoga—Hatha yoga was a long forgotten style of yoga until he revived it—have evolved because of the need of each individual teacher.
Anusara for instance, may well have evolved from Iyengar to suit a specific need that John Friend had...possibly a need to open the heart center more.
I personally teach an Iyengar inspired style called "Karuna" yoga, which was developed by my guru, Ruth White, because back in the 60's when she was studying with BKS Iyengar, he did not want to teach meditation. Ruth and her husband John had a passion for Advaita and set up the style of Karuna to accommodate their love of Iyengar's Hatha yoga and meditation.
It is "mind stuff" and the work of the ego that makes yogis seperate the different styles of Hatha yoga. The particular style they practice might be better for them, but that does not mean it is better than another style of Hatha yoga.
I have had certain yogis tell me that the style they practice is better than my style, even though they've never been to a Karuna yoga class and have actually never even heard of it, even though our styles have the exact same root. This is the same form of group ego that creates the thuggery and vandalism of opposing teams of football fans.
Yoga means to unite, to yoke together, and if the various different styles of Hatha yoga are going to evolve in the west, we all need to be aware that it is all one. We have all branched off from the same source like a giant Hatha yoga family tree.