The global money system (FIAT money) is definitely a pyramid scheme by default. As there are no assets behind a currency, except the value we collectively give it, it is a Ponzi.
But as long as the right to print money is such an important tool for every government, they will fight anything that challenge this right. That is why I believe that BitCoin and any other cryptocurrencies have a limited lifespan. The day the volume of such currencies becoem a threat to the FIAT money, they will be closed down