An example of this and candidate for worst use of a QR code is found on Wifi APs provided by AT&T. A sticker on the device shows a convenient QR code that will get you connected. If you're thinking it uses industry standard Wifi schema well you don't know AT&T very well. Instead it sends you to att.com. That's right, in order to connect to the wifi so you can get online you must first be online so you can get the password from a website.
Fortunately they still print the SSID and password on the back. But it's clear that AT&T would rather you go through their telemetry portal instead.
(And then there's how the signal on it was so weak that it couldn't penetrate interior walls more than 10 meters away. But that's another story.)