DNA: Sleeper bus banned in the world, why not in India?

This is not the first incident of fire in a sleeper bus in Gurugram, 5 such incidents have come to light in the last 2 years. In these accidents, 50 people lost their lives and hundreds were injured. The question is why sleeper buses are becoming moving pyres. After the fire in the sleeper buses, no arrangements have been made to evacuate the passengers safely in time.