Remember Satoshi's goal, the idea of a revolutionary peer-to-peer electronic payment system. Perhaps this revolution has not succeeded, because it is now more developed into an asset because of a system that is contrary to the government.
It is true that bitcoin is not used for mode of payment but as investment but it is what the decentralization and freedom is all about, we get to choose what we want to do with our money with fiat it's what government wants even though we worked and earned it. Also we lack the infrastructure to use bitcoin as currency which may take a while for the transition to happen until that accumulation is the best way to ensure better future not just in terms of returns but also to power shift from centralized banks to the individuals.