We have a system already whereby you can carry a little tiny card of plastic around with you to buy things. It works almost universally. It's already somewhat "killed cash".
And this idiot thinks that now being able to use something that's slightly more difficult to use at best is somehow going to "kill cash" more than it already is?
He's a moron and he's talking stupidly. Debit and credit cards "killed cash" already about as much as it will be killed anytime soon.