A Dubai brunch ended 24 dirhams short, and named the fallacy that caused it

The brunch that turned into unpaid admin

The scene is concrete enough to retell. Six friends sit down for an impromptu brunch in Dubai after a morning yoga class, and a restaurant built to be efficient quietly turns the meal into paperwork. There is one QR code for the menu, so the six take turns scanning it: modern iPhones, repeated failures, nobody actually looking at each other. Mid-meal a parking app fires a two-minute warning, and the table breaks off the conversation to renew a meter from their phones. At the end, six people try to pay their shares through the same QR flow; the interface never makes clear which items are settled. The author's quiet gesture of covering a shared apple crumble has to be announced out loud, and after everyone leaves, 24 AED is still unpaid.

That's the whole post on rozumem.xyz: a field report, not a study. Its frame is borrowed from Rory Sutherland, the Ogilvy vice-chairman whose book Alchemy the thread keeps recommending. The doorman fallacy is Sutherland's name for a specific managerial error. You look at a doorman, decide his job is 'opening the door,' notice a machine can open doors, and fire him, never seeing that opening the door was the smallest part of what he did. Replace the visible task, delete the invisible value. The author's claim is that the Dubai restaurant did exactly this to its floor staff, and the savings on paper bought a worse evening for every guest.

Where the fallacy actually bites: the last mile

The thread's best extension of the idea didn't defend QR menus at all. It moved the argument somewhere with higher stakes.

"My favorite version of this is robotic and drone-based package delivery… you find out just what it is that delivery people actually do, the variety of security systems, steps and walkways, exceptions to rules… what drones and robots automate is not really 'the job' at all." — a former TechCrunch editor now at The Aerospace Corporation

The last mile, he wrote, is not a mile but an interdependent series of distances, each with its own rules; tech tends to solve an idealized, abstracted version and ship a very partial answer.

Someone had to spell out what the doorman is for, because the comments kept treating him as a greeter:

"The Doorman isn't just a greeter… they check that the UPS guy is actually from UPS, they're the first to notice damage to the property, they call the police if they see a crime… things that aren't obviously in their job but things the doorman will actually do." — a longtime HN engineer

He widened it into a software complaint: users are 'killed by a million paper cuts' because engineers now ask 'what's the value?' instead of 'what's the utility,' and a one-second annoyance times a million users is a lot of wasted seconds nobody counts.

"Doormen are a luxury, not a fallacy"

Then the premise itself got attacked, by someone with standing to do it.

"I lived in a doorman building in NYC for almost a decade… literally anyone who has ever lived in a doorman building knows that approximately 2% of the value is that they can open the door for you. No one who is deciding whether to employ doormen is making their decision based on whether there's a cheaper way to open the door." — a former staff engineer at a big-tech company

His point: doormen survive in maybe a fraction of a percent of buildings because they're an expensive luxury, not because anyone fell for a fallacy, which makes them a terrible illustration of one. A second voice pushed from the opposite side, arguing the label has become an excuse:

"People have now clung on to doorman's fallacy as a way to justify keeping outdated jobs around… otherwise we would have people justifying having travel agents jobs and translator jobs being protected." — one reply in the thread

The Dubai asterisk the author skipped

Two replies from people on the ground deflated the morality of the story. One actually lives there:

"I live in Dubai and in my experience the main reason why they want you to pay with QR is because the QR company pushes a service fee on guests and some times even a default tip… Just ask the staff to bring the CC machine. As for the parking… It also got in the way of a $100 fine. I'd say that's a win, not a loss." — a Dubai resident

The parking alarm, in other words, was the system working: a $100 ticket avoided, not a memory ruined. And a developer poking at one of these QR payment flows found that the real cost isn't nostalgia but security:

"I scanned the code… there was a base64 blob on the URL. I decoded it… I changed the check ID (incremented it)… and found I could access somebody else's check." — an IT generalist who fuzzed the payment URL

All he could do was view and pay a stranger's bill, but that a diner with Termux could do it at all says more about these rollouts than any brunch anecdote. The thread's verdict isn't that the doorman fallacy is wrong; it's that this particular restaurant story is the weakest case for it, while the strong case hides one tier up: in the drones, the printed shipping labels, and the IDOR bug, where the invisible work being deleted is logistics and trust, not a pleasant greeting.