There is an interesting book in Hindi published by Gorakhnath-mandir (in Gorakhpur), its title is गोरक्षनाथ और नाथ सिद्ध / Gorakṣanāth aur nāth siddh. There is written following:
आजकल हम विभिन्न प्रकार के योगों के नाम सुनते हैं – राजयोग, हठयोग, ज्ञानयोग, लययोग, भक्तियोग और कर्मयोग| ये शब्द आधुनिक शब्द हैं | प्राचीन योगियों की इसमें आस्था नहीं हैं |
In modern time we have heard about many varieties of Yoga: rajayoga, haṭha-yoga, jñānayoga, layayoga, bhaktiyoga, also karmayoga. These terms are modern. Ancient yogis did not believe this.
I do not think that all these varieties are completely modern, however, in this statement there is much truth. A person who is limited to a vision of yoga in only one category, is unlikely following the right yogic direction. While modern styles of “haṭha–yoga” sin even more, they often lead away from the main yogic goals, they are feeding people’s ego instead of giving liberation from it. They create confusion in the people’s minds, instead of freeing oneself from it. And this mass situation is paradoxical, as often what is called yoga, on the contrary, leads away from the yogic path. Yoga is the integrity of own nature, and how you will come to this and call it is a secondary importance think. It is no coincidence that the term upāya can be translated both, as a method, as a ruse or a trick.