Bitcoins have three useful qualities in a currency, according to The Economist in January 2015: they are "hard to earn, limited in supply and easy to verify". Economists define money as a store of value, a medium of exchange and a unit of account, and agree that bitcoin has some way to go to meet all these criteria.
Still boils down as to how people are going to used their bitcoin, do they want it to become a store of value? Or when merchants started to accepting Bitcoin as payment scheme, will people going to used it?
So this kind of arguments/counter arguments are moot in my opinion, as Bitcoin or crypto are really challenging the way old economic systems are being viewed upon, IMHO.