If you go too deep, even the paper money issued by US government has no value. It's just a paper. However, value comes as a result of labor put. Once we put labor and produce something, it has got value. Value is merely a mental thought. When you value something, it becomes valuable, when you doesn't value something it looses it's value. Ancient yogis in Nepal and India didn't give value to entire universe, so they were able to liberate themselves.

About Bitcoin, I call it Bitcoin bubble. Nobody knows what's going on until it crashes like housing market crashed.