I think you might be suffering from a categorical blindness to a certain type of thing humans do.
Let's say I own a private beach. I want to allow my beach to be enjoyed freely and responsibly by a reasonable number of people, whether friends or strangers. I don't want to constantly be cleaning up garbage on my beach. And I don't want the beach to be overcrowded when I myself use it.
So what do I do? Well, I'm sure not going to hire a bouncer to guard my beach. (How would I even tell them who's allowed in, anyway? Can you recognize "irresponsible people" on sight?)
No, instead, I will probably post a sign outside my beach, saying "NO TRESPASSING".
But I won't enforce it! And if anyone (e.g. my few direct friends who I invite to hang with me at my beach) asks, I'll tell them I won't enforce it! They can bring people to my beach if they like!
Access to the beach is now an open secret. It's something that people can freely tell those they trust about. The number of people visiting the beach will rise slowly over time. Maybe it'll eventually increase to be too much; or maybe it'll level off, due to churn in the population near the beach. (Mostly depends on how hard the beach is to access, and the demographics that live nearby.)
If some tour company tries to drop off a whole busload of tourists at my beach, though, I will most certainly kick them out, pointing at the "NO TRESPASSING" sign. (Since I don't have a bouncer, probably what I would actually do is call the cops on them.)
The cops would ask me about the people already on the beach, of course. To which I would say:
> Those people on the beach right now? They're my "friends." No, I don't exactly know them... but I know people who know them! They're "on the guest list." But these people standing by the bus over here — these are not my friends. These are people brought here by a guy trying to profit off of providing others access to my beach, which I have not granted. They are not allowed in. Nobody brought here by this bus company will ever be allowed in.
This is every underground party ever. This is every travel destination for the rich. Open secrets, with guardians who actively lie by exaggerating the restrictions or conditions in place, to keep a lid on the spread of the secret.
And this is a thing companies do constantly.
• Every store discount code given out to some YouTuber to give to people who watch their thing? Open secret. (Consider: is it "legitimate" for a discount app like Honey to find and publish those audience-targeted codes? No, probably not; Honey would be acting like the tour-bus operator above. But would the online store mind if you personally found the code and used it, despite not being a member of that Youtuber's audience? No, they'd be happy to have your business. Would they even mind if you told three friends, and you all immediately bought something? No. In fact, they'd be overjoyed!)
• The unmentioned (and implied to the contrary!) never-ending-ness of the free trial period for WinRAR? Open secret. (If WinRAR never implied you had to buy it at some point, nobody would have ever bought it; they'd just consider it freeware. But you don't "have" to buy it. It goes on working forever. Some people feel guilty or pressured, and do buy it. Others eventually discover the bomb is a dud. This is WinRAR's intended business model.)
• The CPU binning lottery? Open secret. (Did you know you can keep RMAing retail-purchased CPUs until you get a really highly overclockable one? You do now! And people have been doing this for decades! CPU vendors don't care—in fact, they want these few super-enthusiasts to get their hands on their best CPUs, since they'll probably publish some really nice benchmarks with them. Free advertising! They certainly don't want a company doing this in bulk though. That'd be way more trouble than it's worth; and then what would they do with a huge pile of RMAed known-below-average-binned CPUs?)
• How easy Photoshop was to pirate in the pre-Creative-Cloud era? Open secret. (See my sibling post.)
You can exploit any/all of these if you know (and you're not in a situation legally preventing you from doing so — e.g. corporations can't pirate things.)
And some people know; but most people don't.
This equilibrium state is exactly the point aimed for by the corporations that create these open secrets. They don't want these secrets known by everyone. (If enough people do it, then it's no longer a marketing expense, but a hole in their business model.) But they don't want these secrets known by nobody, either.
The creators of any open secret, want some deserving people to take advantage of the open secret; otherwise they wouldn't have made it an open secret. (In almost all cases, you have to actually do extra work to make something an open secret. It's extra work to carefully design and manage the "virality coefficient" of an open secret so that it'll hit equilibrium, rather than spreading to fixation or dying out. The outbound word-of-mouth advertising required to get an underground party to happen, for example, is way more work than just putting up posters! It would almost always have been easier to just have no secret at all!)
I hope you will agree with me that this dynamic exists in general.
If you do: what then leads you to believe that what Apple has here is a dumb unenforced mistake, rather than an open secret?
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One extra point, that doesn't have a clean place to insert above: corporations are really careful with the way they structure the wording of the exaggerated-restriction "wards" shrouding their open secrets.
For a person, a "TRESPASSING A-OK" sign would just be a sign. But for a corporation, any positive criteria they give implying that a group does qualify for a certain promotion, can be taken as a legal promise on their part.
If Apple offered an obscure promotion to "anyone who can find it" — some secondary secret version of their online store that just happens to have lower prices, say — and then some bigcorp found it... and if Apple then attempted to refuse to apply those promotional prices to that bigcorp's 100k-seat volume purchase of Mac Studios or whatever they were trying to get away with — then the bigcorp could actually be in their right to sue Apple for breaking the promise they were making by having such a store available without qualification! (a.k.a. promissory estoppel.)
(To be clear, to win such a case, the bigcorp would have to also prove that they then went out and did something under the assumption that they could get those 100k Mac Studios at that price — bought 100k Mac Studio-shaped desk nooks, say — and that by being refused the promotion, this contingent action has resulted in a financial loss for them — e.g. if it turns out the 100k nooks have zero resale value, so they're out the cost of the nooks, and also have a huge pile of useless plastic it'll probably cost money to dispose of. But that's not too uncommon of a problem to have, in a big-enough corp with many async/concurrent/pipelined corporate purchasing negotiations going on. So it's something the legal departments of vendors like Apple are always wary of accidentally getting tangled up in.)
"Students and teachers" is a particularly nice/"safe" wording for open-secret shrouding language for a corporate promotion, because there is no case in which a corporation qualifies as a student or a teacher. And yet literally anyone else can become a student at any time, just by signing up for a zero-tuition-until-you-take-courses online university program and nabbing the resulting .edu email. (By the premise of continuous education/lifelong learning, we are always students!) "Students and teachers" is a group that any price-conscious motivated individual can join trivially (just like clipping a coupon!), but which keeps the corporate-buyer discount-loophole-hunters out.