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??
Either they have business interest to protect or they are just totally dumb to understand that Bitcoin is great. Since aside from that there's no point for them to hate Bitcoin since if we talk about volatility fiat also moves that way although Bitcoin is more volatile but for sure if regulated right they won't think that this is an issue.
Fiat is also been used for illegal activities such as crimes you mentioned so I guess this is just their excuse so that the system which they are benefiting a lot by those corrupt officials will not be eliminated. Since for sure with the existence of Bitcoin they might find this asset hard to control.