BTC could make people more autonomous, self-resilient, being their own bank. You can use it like cash, making your transaction almost untraceable (or untraceable using e.g. monero or dash or laundry systems) : this is governments worst nightmare, isn't it ?
The government is having a hard time tracing bitcoin because it is untraceable. Another reason is because it costs so much, it takes great effort for a government to remove a commodity of great value from the market. It'll cause chaos and will most likely cause major fallouts in the digital world. Finally, I think as well as most people here, that the government actually is trying to make some sort of a money making scheme from bitcoins that's why no one still is taking an effort to ban bitcoins after China.