Here's an economics problem about bitcoin as a store of value I want to see Marcus and Adam even attempt to address. The post is a reply to a Nick Szabo quote I don't think is correct:
Any commodity that can be stored and so traded can be used as store of value that will render the owner immune from the perceived or actual risks of holding a floating currency.
First of all, just about every currency is a "floating currency" unless the entire supply has been entirely mined from the closed ecosystem and you no longer have to worry about cost of production affecting value. But even then, you're still governed by people's sentiment for how much they value that object to trade their goods and services for vs bartering with something else. Everything about the currency is going to be floating in one way or another.
Secondly, bitcoin having a potentially wildly floating cost of production is one of it's greatest weaknesses and one reason it's not a store of value. A wildly volatile to the downside cost of production is a black swan event in itself and would render confidence in that asset to nothingness. If we lived in an open ecosystem, which anyone who claims we will be mining asteroids for metals does, then the cost of production and it's ability to not plummet is the main factor that makes gold a store of value at all. If you live in a closed ecosystem it's not that big of a factor since you're bound by supply.
As for bitcoin, the fact that mining NEVER ENDS is exactly the equivalent of using gold as money while being in an open ecosystem. If cost of production craters, you're screwed. This can happen in bitcoin easily. The act of previous holders just hoarding their money and refusing to sell low doesn't help because the network is officially dead in the first place if there's no mining fees to siphon off at this new lower cost of production, so the fresh lower cost of production coins drag everything else down with it.