Government power over money
When you stop and think about it, a lot of governments have nearly orwellian power over money. The monetary policy is not something that is often discussed by a lot of people, and often we are not equipped with the vocabulary to talk about it (like trying to form complex thoughts in newspeak). They get to decide whether savers or borrowers have it easier by controlling the rate of inflation. They get to determine how much your labour is worth by engaging in currency wars and a "beggar thy neighbour" race to devalue its currency the most. Then we have the incompetent governments that let their currency devalue in hyperinflation like Venezuela (reaching about 100+% in 2015). The fiscal and monetary policies are thrust upon us.
In short, the governments can effect our savings, future income, as well as many other factors just by controlling how money is created and spent.
Lack of trust in the government
For those and other reasons, some people resort to moving away from the government-issued currencies and adopt new forms of payments. Whether they take the form of local currencies, gold or something else, they can be an expression of lack of trust in the government.
However, there are limitations to a lot of those currencies in the modern world. Local currencies are often low-tech and they are not usable globally. Physical currencies can be seized by force (like in 1933 in USA, by the Executive Order 6102).
At the moment it would appear that only native cryptocurrencies such as Bitcoin can be a viable protection from the government in the modern world.
Protection from the government
While some people would jump to thinking that "protection from the government" necessarily means breaking the rule of law and engaging in illegal activities, that's not what I'm talking about here. What I'm discussing is withdrawing at least partially from the fiat-fuelled economy and moving into the cryptocurrency economy. One can and should still pay taxes, obey the law and so on, but that doesn't mean one has to keep one's wealth in the potential house of cards that various banks and government currencies are (look no further than the 2013 Cyprus crisis and the related bank bail-ins).
I am a saver, not a borrower. I wish for my money to at least keep its value, or be worth more. I want my wage to be stable no matter which government I work under. I don't want the currency I use to be created as debt by the banks, or even let the banks take any part in the money creation process. As such, I know of no fiat currency in the world today that satisfies my preferences, hence why I choose Bitcoin over fiat.
Native cryptocurrencies like Bitcoin offer a way for people to de-leverage the power governments hold over the currency and shape a new economy for themselves.
The IMF and similar organizations need to understand that asking "should the government regulate cryptocurrencies?" might be less important than "if cryptos will succeed, why would anyone continue to use fiat?". Probably for the first time ever, fiat currencies have a worthy competitor in the global Internet economy. They can either focus on becoming the best currencies they can be to compete (akin to Steam trumping free torrents), or go the way of the Kodak.