I really dont know why bitcoin is still here but in my opinion there are big men who are keeping it protected and they are also into bitcoin that is why it stays. The government can ki bitcoin if they want to. But there are people out there who are stopping it.
Everyone is aware that what government as done so far for the betterment of country and society. They are just busy in filling their own pockets with black money and scandal and scams if they start supporting bitcoin then it would end all their corrupted activities.