Re: "A QR code can easily contain a link to a scam or a blob of malicious binary information"
I think that was meant to be read with slightly different emphasis:
"A QR code can easily contain a link to a scam, or a blob of malicious binary information".
OK, any form of URL can link to malicious content, but I think the point is that the QR code itself has enough space in it to contain a useful buffer overflow targeted at the QR software itself.
Not many people would type in a printed URL like "http://www.theregister.co.uk\n\n000000000000000000000000000000000000000000000000xdeadbeef", but a QR code neatly gives you the ability to blob that right up.