In his own reddit AskMeEverything page,
https://www.reddit.com/r/IAmA/comments/80ow6w/im_bill_gates_cochair_of_the_bill_melinda_gates/He answers about cryptocurrency stating
The main feature of crypto currencies is their anonymity. I don't think this is a good thing. The Governments ability to find money laundering and tax evasion and terrorist funding is a good thing. Right now crypto currencies are used for buying fentanyl and other drugs so it is a rare technology that has caused deaths in a fairly direct way. I think the speculative wave around ICOs and crypto currencies is super risky for those who go long.
He isn't wrong in his sense, if the cryptocurrency is to have a future, they should be able to create an environment of trust between themselves and the authorities.
Bill Gates speaks badly about cryptocurrency, arguing that the anonymity in it is bad. In our age of universal control of the government over a person, anonymity, even in this, and the anonymity is far from complete, is very good. Technologies, as a rule, presenting us with certain amenities, deprive us of our right to privacy. This is especially true of mobile phones, thanks to which our life has become in full view of the relevant services, which can see where we are, what we say, and so on. Cryptocurrency gives at least some financial freedom, which over time will still be cut.