There are a large number of people living in China who would like to get around the nation's currency controls. There are a large number of people living in Russia that want to move money without being tracked. There are a large number of people living in Latin America who want to avoid taxes in their own countries. This is what drives the use of Bitcoin. The only large scale need for Bitcoin is criminal activity, in China, Russia, Latin America and elsewhere.
Currency regulated by the government is a classic "good enough" product. It might lack some features that would be nice, but 99% of the public doesn't seem to care. Rather, they want more money, but they don't want to change money. If they had real doubts about the currency, they would dump it in exchange for real goods. But instead, most people work hard to acquire more money, and they show no real concern with the standard proxies for currency (credit cards, checks, etc).