I come from a lower-middle-class family in Kolkata, and I can say from experience that a lot of older people (my parents!) are over the moon with the whole thing. My mother, in particular, has suddenly turned into some sort of Modi fangirl, saying stuff like, "See what he's doing for the country!" (and variations on that). At some level, it's just the fact that anyone who replaces years of (perceived?) inaction with something striking -- however naive, or well-intentioned-albeit-disastrous-in-the-long-run -- will elicit this kind of reaction.

I imagine for people like my parents, the cost of going to a bank and getting all their suddenly-demonetised banknotes exchanged (which we anyway had very little of) isn't too much. And when some restaurant, say, or a drugstore, is unwilling to accept one of the new 2000-rupee notes, we have credit/debit cards to fall back on. The fact that that people may not have Aadhaar[1] cards or voter ID cards stored safely somewhere, that not everyone has bank accounts which hold >99% (excuse the arbitrary figure) of the money they have, that not everyone has the ability to spend what might possibly be the better part of a day walking to $DEITY knows where the nearest bank is (probably to be turned away because they're out of cash or because the line is a kilometre too long) -- that the very act of going to a bank may not be as trivial or no-brainer-like to everyone as it is to oneself! -- is something we have to work very hard to even imagine. And the cash they have stored is, in many cases, all they have. (Remember what I said about not having a bank account?)

Cash, for us, is what we use for bags of chips and ice-cream and sheets of graph paper and ... bus fare, I guess? Cash, to someone living from day to day, is everything.

edit: yay downvotes, I can tick that off my list

[1]: https://en.wikipedia.org/wiki/Aadhaar