Right, the source isn't important. What matters is whether what you've received is, for practical purposes, actually currency.
If your boss showed up and said "from today we're going to pay you in bananas, and our exchange rate is $1000 per banana. By the way here's a raise too" and drops a bundle of bananas on your desk... Would you consider yourself paid?
Bananas aren't even fiat! You gotta grow them first
This is a silly example, since in the article there's clearly consent on both sides of the equation. But if the coins remain as "e-points" in their system and there's not much incentive on the buy side, they're not super useful as currency.
In practice the crypto currency markets seem to fuel a good amount of liquidity. This is a pretty neat side effect of the block chain boom.