Exactly my thoughts
QR codes are blindly obvious targets for scammers. You have no idea what is contained in those codes. The same goes for URL Shortening.
I did try a QR code once. Led me to a Pron site before I could blink an eye. Thankfully I'd booted off an Linux DVD and used it from there.
I've been asked to scan QR codes to get discounts. Nope. Don't trust them.
Sorry but IMHO these both fail in big ways.
You really don't know what you are letting yourself in for.