Some countries were already banned bitcoin, and here in my country they did not banned it not because they don't know what to do but they find bitcoin as an interesting and a great opportunity for the people, and a big help in our growing economy.
I think every country should follow this opinion because we know bitcoin as great opportunity in the field of economic.
Country which ban bitcoin has a lot of thing to think but most of the reason is cryptocurrency decentralized. Not control by them.