The point is to sabotage the business in a more impactful way than merely walking away. Harming employee morale, and consequently employee retention, is an effective means of protest. If the employees get a sour mood about it and give other customers worse service, all the better.
On the other hand, you're being an asshole to someone that has to stand there and take your shit because they have debts and a rent to pay. And, since they deal with people all day, they know that moving to another work place with a paper menu won't fix anything because there's always some asshole that will do their best to make them feel like crap.
Not to mention that the average person doesn't understand how online menus can be a problem. Most don't understand how tracking works, for example. So when you leave, things go back to normal because that was just one of those customers.
Menus on QR codes is a problem. People that behave like you are also a problem. I dislike both.
As someone who works in the industry I can assure you that you're not harming morale nor affecting employee retention in the slightest. Being an asshole doesn't make you relevant, it only makes you an asshole
