Bitcoin has value because it is a coin widely known worldwide. I don't think there is any possibility of Bitcoin going down to 0 because the demand for Bitcoin is increasing day by day. As the demand increases, so does the value of Bitcoin. As long as there is demand and use, its value will remain the same. I hope that in the near future Bitcoin will play an important role in international trade and transactions.
I don't think Bitcoin is valuable because it is widely known? What about the days where people don't know Bitcoin and only few knows it? what value did they saw to mine Bitcoin? you see, it's not Bitcoins popularity but utility and it's technology that brings people to use it. Without it's semi-anonymous feature and its decentralization, then people wouldn't even bat an eye.