Because they're actually using it as a currency. Consequently, they probably won't feel as much of the pain speculators are feeling right now / will continue to feel; as long as the amount of $FOO earned from a day's work pays for the day's expenses, they have little reason not to continue adopting and using $FOO (for whatever value of $FOO we're using).

Put differently: when the options are "failed local currency" v. "hard to obtain foreign currency" v. "easy to obtain electronic currency", you and I would probably be inclined to use the third option.