Governments, banks and other financial institutions have long ignored the bitcoin. Because in 2017 the bitcoin gained 1500% in value they are suddenly realising that bitcoin may become a serious threat to the traditional monetary system. Now economists, bankers and politicians are suddenly issuing warnings. Most of them do not have a clue what they are talking about. Cryptocurrencies are a paradigm in economics. Without really understanding the impact of this game changer they suddenly propose to restrict or ban crypto trading. The real reason for this is fear for change but the fake reason they mention is that they want to protect the people against the huge risks that are involved in crypto trading.
One issue they mention is that cryptocurrencies are not backed by real value like fiat currencies. Unfortunately that is not true. For fiat currencies the gold standard has been abandoned many years ago but there are a few cryptocurrencies that are actually backed by gold. For many years most governments have been exceeding the available budgets of their fiat currencies. The only backing fiat currencies have is a huge government debt. In order to be able to handle the huge debts that these governments have created they need to manipulate the monetary system. Interest rates are artificially kept at a very low rate and inflation is being stimulated. The real value of fiat currencies has decreased considerably over the past years. In the Netherlands the price of a beer was 1,25 gulden 40 years ago, now a beer costs 2,50 euro, an increase of more than 300%. And it is not just the price of a beer that has gone up like that, the same is true for e.g. real estate: a house that cost 125000 gulden 40 years ago will now cost approximately 250000 euro. Many governments have simply just printed all the fiat currency they required causing the real value to decrease. Cryptocurrencies cannot be manipulated and that is bad news for those governments. Most cryptocurrencies have a clearly defined limited stock available. With growing acceptance the prices will go up and that can be seen as some kind of interest.
Another issue that is put forward by the financial world is the high volatility of cryptocurrencies. That is a problem but one of the main reasons for that are the many confusing announcements from regulators worldwide. For example on the 11th of January the South Korean ministry of justice announces that they are investigating a total ban on crypto trading and on the 1st of February the finance minister announces that this is definitely not going to happen. If worldwide regulations are becoming more clear the volatility will get much less.
Also recently several high profile economists, bankers and politicians have made negative statements about bitcoin.
An example of that are the statements made in September 2017 by JP Morgan chief executive Jamie Dimon: https://www.bloomberg.com/news/articles/2017-09-12/jpmorgan-s-ceo-says-he-d-fire-traders-who-bet-on-fraud-bitcoin. Here he announces that he would fire any employee trading bitcoin for being stupid. As a result the value of bitcoin dropped about 10%. He obviously didn’t know that his bank was already involved in bitcoin trading and a month ago he has stated that he regrets calling bitcoin a fraud : https://www.ft.com/content/e04e359a-e9e9-3f8e-8e2f-3f4373e5efb0
A more recent example is Stéphane Boujnah, the CEO of Euronext, who compared the bitcoin with a Pokémoncard:
https://www.bloomberg.com/news/videos/2018-01-30/euronext-ceo-sys-bitcoin-has-nothing-to-do-with-real-economy-video
The European Parliament, the World Economic Forum and the G20 are currently discussing how to deal with bitcoin. As far as I know Pokémoncards have never been discussed on platforms like that.
I do expect that when the ignorant mastodons of the financial world are replaced by people who actually do understand the importance and possibilities of cryptocurrencies their confusing statements will disappear and volatilities will become acceptable.