Cash

That nice Mr Darling has told Mr Bank that he must give basic accounts to poor people so they can pay their bills and not be excluded from society, because he is a nice man and he feels sorry for these poor people.

It's really nothing to do with the fact that these people are dealing in cash, and when you deal in cash that nice Mr Darling can't get his thieving mitts on your money because he doesn't know where every penny of it is going, every second of the day, oh dear no, what a suggestion.