To my best knowledge some government scared of bitcoin for different reason such as:
1. Because they can't catch people using cryptocurrencies for criminal purposes, several governments do not want to lose control over their financial systems. Therefore, this virtual currency is feared in some economies.
2. Due to their observation of the rate at which bitcoin is expanding globally, the majority are afraid that their own local currency may lose value.
3. Due to Bitcoin's volatile value, the majority of people do not believe the idea of this virtual currency.
and lot more.