I just think like; when Bitcoin comes up to the world for the first time, they don't care about it instead of thinking that Bitcoin will "attack" fiat money. Then users are still growing, so they are thinking this is a "war". But finally, they can see that Bitcoin still can give huge benefits to their country, so the "main leader" is saying "let's regulate them".
Banning bitcoin has twofold problems:
1. Putting a ban on something like bitcoin means cutting down electricity and internet to a region, because these two things are essential to run a wallet and transact. This leads a lot more problems than solutions.
2. Banning something in general only raises public curiosity about it.
Coming to regulating bitcoin, government want to generate taxation from capital gains, so regulation is the two pronged sword here, it is a method to monitor the gains and keep launderers at check. Therefore average honest users will not face big problems with regulation.
Majority of the people who are against regulation have illicit bitcoins at hand, and hence they want to save their asses.