> I've never scanned a QR

That's okay. It's also okay to prefer a paper menu (I'm the same).

> I don't intend to learn how

I mean, no one is forced to learn, but knowing stuff is not a bad thing. It takes less time to read a QR code than to type that reply.

> I'd be compelled to stick around for a few minutes loudly insulting their business

What happened to calmly explain your position and then leave without giving that business your money? You don't have to be an asshole to the person serving you... in fact, they probably don't have a say on the matter.