The value of a thing is nothing more than more the price which people are willing to pay to acquire it.
So, why would you choose an unstable, national currency over a more stable, international one? As many african countries can attest, having your own currency is only effective if your economy is stable.
Oh bla bla bla! Debts have been zeroed out hundreds of times.
Yah, true. Have a look at Greece's debt for the past 200 years.