Other drawbacks of the blockchain noted by the economist are security and decentralization.
This is really lame. If anything, the decentralization is one of the main advantages of the blockchain.
Rubini noted that cryptocurrency exchanges are constantly becoming victims of hacker attacks, while almost all of them remain centralized, despite the emphasis of technology on decentralization.
The same argument about being susceptible to hacking can be made for the current technology,e.g., for companies that accept credit cards. A very recent example is the British Airways Hack:
https://www.telegraph.co.uk/news/2018/09/07/british-airways-hacking-customers-cancel-credit-cards-airline/
Perhaps, with the emergence of new opportunities use technology in economic relations Rubini can look at it with other hand, and can and at all will change its opinion about it.
We couldn't care less if he changes his opinion or not, but he definitely needs to educate himself if he is going to criticize the cryptocurrencies.