yes, because they think bitcoin is a threat to their currencies and the world. so they are assertive against bitcoin users.

Well, that's their own problem if they are going to look on the good benefits that bitcoin have and only look on the bad effects or bad benefits they are not understand it. There are some people did not understand the flows of bitcoin because they are not interested on about learning it.

The best thing I can think of is taxes. If you could earn money in something that has value but isn’t reported, that would mean the Government is losing out on income and governments hate to lose out on tax income. Another thing is the ability to manipulate and control the currency. If they lose their control over money creation, then they lose the ability to manipulate market conditions. The fact that bitcoins and other cryptos cannot be controlled or regulated is enough to make government fear it.

as the matter of fact government always declined bitcoin to do an investing.  because of its dark side and also a lot of scammer involved in bitcoin such as stupid scammer copying the design of some classified site and shows some false testimonials to scam some of the investor, i think that is the common reason why government didn't accept bitcoin because of that scenario.

In my opinion, Bitcoin takes no reason for fear, because Bitcoin is easy to spend income through a digital currency,
The easiest way people want to deal with is the world around. And Bitcoin is its only easy way,

Bitcoin takes no cause for fear, but be cautious because some opportunists want to take advantage of using Bitcoin, and some governments work against Bitcoin because they make more money by deceiving the people of the country. But they do not earn much profit due to Bitcoin transactions, so they work against Bitcoin. Bitcoin is not doing anything to deceive ordinary people, so there is no reason to fear Bitcoin.

Perhaps every government has right to use their own rules in their country. The advanced countries like Japan is accept bitcoin as legal currency. But some country stops their citizen to invest in bitcoin this is because of rigid thinking, they feel threat from bitcoin that it has no involvement of any other person or government. They want to control over the entire money builder in their country. They are worried that some criminal mind people will not take benefit of bitcoin by its independent quality.

The answer is very simple. Governments want to have their share of the country's crypto-currency operations. But they can not impose taxes on taxes. It means that they will frighten their citizens in various ways and hinder trade in crypto-currencies.

The biggest and the only fear of bitcoin is that it might not banned by government and this is the only reason government keeps on notifying citizens not to invest into BTC. Being decentralized cryptocurrency, government is not liable to impose tax on the transaction of BTC and that's why they don't want that their citizens invest into BTC but instead of all these, intelligent business man invest into BTC coz they know BTC is profitable.

The government should be on the SAFE SIDE ALWAYS.
They will tell you that it's dangerous to avoid chaos on the economy system and panic on the people.

Do you think all your government officials in India has no investment on bitcoin? I don't think so. Maybe few of them are whales. Who knows bitcoin don't require your personal identity.