Many government are seeing Bitcoin or cryptocurrency as a threat to their financial system and they think it should be regulated to solve the problem. Do you think they can regulate Bitcoin ?
I don't think that any government can regulate bitcoin alone, because they can't control Internet.
Only some kind of regulation on the world level is possible, but I doubt it will happen soon.
Governments can control income from bitcoin and crypto currencies when you decide to exchange your btc funds to the fiat money.
In the most countries, I believe, you will have ti report it and pay tax.
No government can regulate bitcoin because it is a digital currency, people don't see it physically unless virtual, how can you regulate something that you can't see physical? Also, bitcoin is decentralized and secure, even if you can see someone's bitcoin wallet via blockchain explorer you can't control it because you don't know the owner and the private key as well. Regulating bitcoin is like regulating air in a football field which is a big waste of time.