Hit the nail on the head

https://ftalphaville.ft.com/2018/01/12/2197556/crypto-fiat-coin-confusion/

A thing that can often be heard said these days is that central banks should tap blockchain technology to launch their own crypto coins.But there are many reasons why such talk is misleading and distracts from the key issues at hand.
1. In  its simplest interpretation, talk of crypto fiat issuance is almost  certainly a euphemism for something else: the expansion of a central  bank’s digital balance sheet to every single person. Yes, really.
2. If, however,  central banks really wanted to provide digital access to their balance  sheets to every single person they could have done so years ago using  existing technologies. Blockchain, whatever flavour it comes in, is  entirely unnecessary for accomplishing this objective.
3. In  general, as centralised issuers of cash liabilities, there is little  need for central banks to adopt much more expensive blockchain or  distributed tech technology beyond the role such technology might play  in backing up their core systems. Yet, even here, there are alternatives  that don’t compromise system control the way blockchain does.
4. If for some reason central banks did  decide to open their balance sheets to Joe Public, they would have zero  interest in doing it in a pseudonymous or anonymous manner. Physical  cash transactions are drawing greater scrutiny not less, and the move is  clearly towards greater traceability not anonymity. And yet, assuring  privacy is the only other possible justification for using blockchain in  the process.
5. Even in a scenario where digital anonymous fiat  was launched to replace physical cash entirely (say to make negative  interest-rate policy easier to implement), this would not go down well  if the cost of the move was less traceability of illicit funds through  the system.
6. All of this implies that the reason central banks  have not yet extended their balance sheets to everyone universally is  not due to technological limitations as much as socio-economic and  structural factors.
7. Given the above, why in all the talk of  crypto dollars, roubles and yens are none of the socio-economic and  structural limitations ever being discussed?