There is way too much human interest to that article and way too little substance on the problems. Tl;dr - there’s no security risk unique to QR codes are that aren’t simply present on the Internet at-large.
Also, QR codes obfuscate the request that is being sent.
There is an inherent security risk... it is trivial, as the OPs article suggests, to print out a QR code, cover an existing public one, and send people to a phishing site. Unless people are being very careful about what sites they are on, they could easily be scammed.