The way I see it, Nest and Ring are a $20 doorbell, plus a $10 range extender so you can hear the bell if you're out the back, plus a $170 home CCTV system because you're in a high crime area.
Seems to me a QR code removes the $170 bit that was a key part of the Ring camera value proposition.
I'm in a very low (nonexistent, really) crime area and I like the camera on the doorbell. Not worried about anyone breaking in, but being able to tell at a glance whether it's a package, a neighbor, or a salesman ... that's valuable.
The "ring me even if I'm not at home" feature has some value also.
And for people who do not live in high-crime areas, but might want the other features of a Ring camera, the value distribution would necessarily be different.
Seems to me a QR code removes the $170 bit that was a key part of the Ring camera value proposition.