Bitcoins operate off central Banks meaning the government can not control its supply or influence its value like they do with fiat currencies. This threatens their ability to manage national income. Also since Bitcoin can be pseudonymous, the government worries that people may use it to evade taxes, launder money,Or finance illegal activities.
Why are some embracing it while others seek to regulate or restrict Bitcoin??
Simply, most old governments or let’s say the controlled ones by other stronger governments are less interested in Bitcoin for their lack of information about it and the fact that this coin can give their people more financial freedom over their funds and easily skipping to pay taxes. While these kind of governments are trying to fight Bitcoin, other governments discovered that the only way or the best way is to control most of the circulating supply of Bitcoin, and have more of this money than any other country.
Let’s take for example USA, how they started fighting Bitcoin, just few years later, now they are trying to own more quantities and showing support for crypto market.