Well, due to Prime Minister's Jan Dhan Yojana scheme, a lot more people have bank accounts and debit cards now. Over 220 million bank accounts were opened since 2014. People who have those accounts can actually make use of them now.
Now it was a known fact that 80% of the currency will go out of rotation. Now regardless of whether you have an account, 80% of the money people use to trade is gone!
Doesn't help if you have a account either. You don't have money to buy stuff.
Your point is if(and that is a big 'if' given 80% is gone!) you have money you could deposit it. Not spend it.
Now I'm not saying that this won't be possible. But its just these kind of changes can't be done with a throw of switch. You need to do a lot of incremental work before you can even think of this kind of big risky moves. Roll backs are hard, and in this case impossible(will lead to increase in inflation if done). Nor can you sit down quietly as there is no real way to put money back into circulation.
We all want to change the world. But we have to understand we need to change the world with consensus from people we want the changes to effect. The world is not in a hurry, and everything/everyone has their own priorities. You need to work with all that. Tech idealism is great, but at times something like this comes to remind us we know nothing about the daily complexities of other citizens.
[1] http://economictimes.indiatimes.com/news/politics-and-nation...