Why do people do Kundalini Yoga

WHY KY? Why do people do Kundalini yoga? I have interviewed some dearest fellows - KY yogis. And I have asked them 5 questions: 1. Name 2. How long have you been doing KY? 3. Why do you do KY? 4. What is the biggest challenge for you in KY? 5. What is the biggest joy for you in KY?