As long as bitcoin has intrinsic value (which we agree it does), the price can boom due to economic conditions, just like the precious metals.
where's the intrinsic value? i don't believe anything has intrinsic value in the great scheme of things. value's awarded and mutually agreed, it's not a concrete thing.
you're right, all value is necessarily subjective because value is a human construct that doesn't have an object existence you can prove with experimental or observational evidence.
However, Landauer's principle of information theory ensures that entropy-increasing, irreversible computations (like bitcoin's proof-of-work hashing) consume a quantifiable minimum requirement of energy. Energy is an objective, extrinsic property associated with many different tradeable commodities that are widely marketed. i.e. valuable, across the planet.
But energy is just an underlying need in all things based on computational technologies, and we have just founded this critical issue a priori, so the potential value of bitcoin was never calculated based on its energy consumption.