I think they will ban bitcoin because of the fearful that may affect of the economics of my country but i disagree there opinion because working bitcoin is very helpful for me especially the support financial.
Any government who thinks about banning bitcoin or any crypto currency fear about money laundering and terrorist funding and that is what they will be focusing to tell if they want to ban them. I am not sure how these cryptocurrency is aiding you financially unless you are holding a good number of coins.
These may be reasons but the primary reason that I think is, it is just their dream to control bitcoin. Every government wants to control the money circulation in their country but as bitcoin is decentralized so it would never be under control of any one so the governments are accepting it as legal currency only for this reason. Human trafficking, drug dealing and terrorist activities, these are just lame imitations.