The Krugman's problem is, that he is used to certain definition of "money", and then when something else comes, he compares it to that definition. For example, the original paper from Satoshi didn't mention the term "store of value". Given the ambiguity of the word "reliable", we can say nowadays that bitcoin is not "reliable store of value". But who said it is? It must not necessarily have the same attributes as fiat money does.
Anyway, I think the root of the problem with those mainstream journalists is that they do not distinguish between Bitcoin as an unit of account (like, I have 0.5 BTC, or this item cost 0.1 BTC), and a Bitcoin as a technology (peer-to-peer trustless network with all the wonderful attributes it has). Their mind mangles those two things into one, and they then see Bitcoins as only some virtual numbers, which are moving from one wallet to another. Starting from this perspective, they can't conclude anything useful, and can't see the intrinsic value of Bitcoin the technology.
Anyway, I think the root of the problem with those mainstream journalists is that they do not distinguish between Bitcoin as an unit of account (like, I have 0.5 BTC, or this item cost 0.1 BTC), and a Bitcoin as a technology (peer-to-peer trustless network with all the wonderful attributes it has). Their mind mangles those two things into one, and they then see Bitcoins as only some virtual numbers, which are moving from one wallet to another. Starting from this perspective, they can't conclude anything useful, and can't see the intrinsic value of Bitcoin the technology.