I think "they" know that their FIAT system is simply bound to fall apart, because they are printing unlimited money. Basically every country has debt. Just look at US debt. They are in very bad situation because their debt is in the trillions.
Spreading FUD might be beneficial for the governments, because they probably wanna get in at the lowest prices possible, before it shoots to the moon. Anyway, there's still a long way to go for bitcoin and other cryptocurrencies. We'll see how all of this turns out.