That's funny it seems that this economist thinks fiat money can't never be valueless. Well, look Cyprus, and look Ukraine now. I am not saying Bitcoin won't never be valueless, but apparently fiat money is not completely invulnerable.
The examples you give, are not examples where just fiat money fails. They're examples of the entire architecture of a society falling apart (the government is being overthrown in the Ukraine, post WW1 Germany was in the midst of a massive recession). These are all situations where no currency retains a stable value since no currency allows you to eat, fuel vehicles or defend yourself. In those situations, Bitcoin is as valueless as anything else (more so, by virtue of being unusable without the internet).
These are all situations where no currency retains a
stable value since no currency allows you to eat, fuel
vehicles or defend yourself.
Seems to me there's nothing stopping Bitcoin fulfilling that requirement.
The currency in use in Cyprus is the Euro - the problem with Cyprus was their dodgy banks not the currency itself.