I can't pay for the labor in bitcoin, I can't pay for the materials in bitcoin, I can't pay closing cost in bitcoin so in effect my house is worth infinity bitcoin right now. If tomorrow everyone lost faith and the price dropped below energy costs, miners turned off their rigs and difficulty dropped then the "energy" the bitcoin is worth would have dropped. Bitcoin is also fiat backed not by any government but by the people participating in the network. Their subjective value of bitcoin says its worth more than the energy so they are willing to spend their resources to get it... I was going to try and make an analogy to options contracts... there is some real value to the underlying and then there is the imaginary value attributed to what it may be worth in the future. As the contract matures the imaginary value diminishes and all that is left is the "real" part. In the future when everyone trusts and has bitcoin it will trade like forex where fractions of a penny matter because the prices dont change that much that fast. The speculators will be gone any one people using it will remain