Some Perspective and Experience While i was in China.
I couldn't set up my WePay in time, so like the Author, I had to use Cash. And from my experience between a Tier 2 City and Tier 1 City like Shanghai, it is actually those Tier 2-3 City refuse to accept cash. They thought Cash were cumbersome. And Shanghai may be more welcoming cash / Credit Cards for variety of reasons ( Likely privacy ).
I tried to buy breakfast for $2, ~20 cents in USD, i didn't have WePay so I paid in cash. The Shop owner said she didn't have any changes and decide to give me the meal for free.
Over the 15 days, I kept thinking about QR code as Tech. Trust me, it is crap. I dont believe there is that much time difference holding up the queue as noted in the article. You have to Open up WeChat, and let each other scan, input your payment by youself, show them you have paid. To me this is very backwards. Octopus in Hong Kong, Scuria in Japan, Oyster Card in London Transport, Offline Mobile Payment from Master Card and Visa, All these are 10x better in UX. The merchants input my bill, I beep. That is it.
Then suddenly one day it clicked, and I knew why QR Code succeed. With NFC or any other Wireless payment, you need something, a electronics, a beacon or what ever for sellers to work. With QR Code, They "Print" a QR Code and laminated it. And you can photocopy as many pieces as you want. The barrier of entry for QR Code is so low every one could use it. At the expense of consumer UX.
And then weeks after I visited China, Apple announced in WWDC, iOS 11 will come with Auto opening QR Code in Camera mode. That, may have just made the friction of using QR Code much more bearable for me. And it is likely both tech will exist side by side in the long future. I cant see QR Code as it is used today ever getting replaced by the more expensive NFC solution, and NFC will likely stay in transport and other areas.