Or just display a short number code. Displaying a QR code won't solve anything, it will just obfuscate the error and leave the user without any easily memorable reference. This sounds more to me like "let's do it because it's modern and hip" rather than it being actually useful.
The QR code can not only indicate the exact location of the error, but can take you to a website on the phone, with a url long enough to log
many key points about the error.
Even if it logs very little, developers will get more input this way than they do now, because when your machine is crashed, you can't report anything and once it reboots, you have other priorities than digging in the last crash dump.
However, other than collecting statistics, it might not do any good. Even when you do submit a dump, you get the request to install debug symbol packages and trigger the crash again. Ah, no, that isn't going to happen. Or there will be necessary drivers installed that taint the kernel, and devs wont touch it until replace your video card, untaint your kernel, and trigger another dump.