Its mainly because the government can't regulate it and track it. The government want to be able to investigate your bank activity if need be freeze assets get taxes since it distributed, Bitcoin exists at many different locations at the same time. This makes it very difficult for a single regulatory power to enforce its will across borders. It also means that a government or other third party can't technically raid on office and shut down anything.

If many governments of the world are against cryptocurrency and and can ban anytime then what is the point of cryptocurrency?