Do you mean leave if they don't have an alternative?

I'm not religiously opposed to QR-code linked menus myself, but it just so happens that the last restaurant I ate at, the QR menu was broken and I was forced to ask for a paper menu anyway.

Now if a restaurant puts a lot of care and curation into a web based menu (and posibly ordering system!), and lovingly craft a complementary QR code to point to it, then why not?

A lot of the time the caring is the important part.

This happened in an airport restaurant. I asked the server to get me the cheeseburger with fries.

Yea, ditto if they only take orders via tablets. Vote with your wallet.

Yes, I have left restaurants because they only offered a QR code menu, and I plan to continue to do that in the future.

If they wouldn't find another to help me? Absolutely. I can't imagine I couldn't just ask the server a question like "what's cheap and good?" or "I'll take the soup of the day."

If they can't be bothered to bring a printed menu when asked, yes.

Restaurants have thin enough margins already. They aren't turning away a customer for not bringing a phone. There's one tiny burger place just around the corner from me that's delivery/pickup only, not even a QR code, but they have a sign outside saying 10€ combos and they're 15€ on the website... I just asked them. They have very good halloumi burgers and perfectly cooked fries. They were happy to accept my cash, too.

I certainly would, unless it was something I was doing for someone else's sake (like a birthday dinner for someone). Why would I do business with a restaurant that can't be bothered to provide a good experience for customers?

yes

Depending on what type of computer (if not smartphone) you have at hand, you can probably use a search engine to find the same menu. Or ask somebody at your table. Or ask the server. Or point at somebody else's food and say you want what they're having. Or eschew the menu entirely and ask to be surprised. Chef's choice can be fun.

Or leave yeah, I think that's valid. TFA is predicated on the notion of pretty-much-lying to people by telling them you don't have a smartphone even if you do. Leaving a restaurant if you can't find a menu seems like it'd be on similar ideological footing.