(Please note that while I use "you" below, I don't mean you `wilfred` in particular, but instead it refers to "The Reader" and I'm just trying to give another point of view for your riddle.)
I have doubts about the relevance of this but I'm reminded of the riddle I first heard in the 1960's Batman TV show. Q: When is a door not a door? A: When it is ajar. Would you still call the door open? You can't pass through it, but it isn't closed. It depends on the semantics of how you define open.
I think this is very relevant "example", because the point actually changes and depends very much on the perspective!
But it also shows why I completely agree with Dave's (EEVBlog) point on why the word "open" (hardware) can't be defined in terms of black/white or true/false (at least not in the hardware world).
The riddle's meaning will immediately change as soon as
you have a stake or "skin-in-the-game" if you like.
If door (or something) is not open, then it must be closed?! Right?
If this is true, then if the door to your house is ajar, why do you bother closing it? Why not leave it ajar since it's the same thing as closed? It's definitely not _fully_ open, so that means it's closed, right?
I think it's probably because now
you have a stake and want to make sure you (and your property) remain safe.
And you know that depending where you live, even if you leave the door ajar over night or many nights in a row, it does not mean someone will break in right away or something horrible is going to happen.
But I doubt you would consider a front door to your house that is ajar closed or sleep well at night unless it's fully closed.
The same goes for open door, how much open door is open? 45 degrees, 60 degrees, 180 degrees, door off the hinges? You don't need the door to be _fully_ open to enter, however if you are moving in a fridge... every bit counts and the more the better. Unfortunately same goes if someone is looking to clone a product or make a profit.
Open should mean there is sufficient detail for a skilled person to reproduce the article and make changes without constraint for want of missing details. Less than that then thanks for the details provided. But don't try to call it open.
I get your point of view and you have every right to it (and as a hobbyist I agree with you completely). Unfortunately, a lot of "business" often use "open" hardware/software as a marketing keyword and to gain attention/publicity.
But we are talking here about
open hardware, not open software! So in this case we also have to define what is "skilled person" and what does that mean? What tools and materials they have access to?
I understand why for example CERN releasing every possible design/document for their particle accelerator as open-source and open-hardware does not bother them much. Good luck building those in China for cheap and selling them on eBay/AliExpress.
Okay, maybe a bad example because this is "academia" and sharing and peer review is "necessary", but the point on cloning and selling those designs still stands.

But at the same time, someone making a product (not a half-baked weekend/hacky project but an actual "polished" product) and they decide to release complete schematics (maybe even with pcb layout) and firmware source code. But they don't provide gerbers, pick and place, BOM and other files needed for (mass) manufacturing.
Now you can can understand how it works probably learn something new/cool from the schematic/layout and also make modifications in whichever way you want or integrate it into something, because they provided the documents for you to know the "ins and outs".
To me this is very open and what I would like consider the threshold for "open" hardware project (but again, I'm just offering my point of view).
But I would love to hear why this is not "open hardware"?
This might be a very unpopular opinion but it's my own and we can have different ones and still be friends.To me, this is not the same as "open software" and what really grinds my gears is that for (a very vocal minority of) hobbyist people, the issue is not about:
"Hey buddy, I would love to share my time and expertise so I can help you with this schematic/layout or I can help you optimize the BOM or add a firmware feature, that's what Open is all about".
But instead it seems to me that (again, vocal minority is making) the situation more along the lines "This is open source world buddy, hand over _everything_ that you have and that you know or else we will bully you into submission! And don't even think of hiding something, because cavity search is part of the process. Why? Well because that's what open means buddy and you made a mistake of calling your project open on the internet!".
Don't get me wrong, as a hobbyist, I love "open", and the more open stuff you give me the better. That's very greedy of me, but it's in human nature and also I have zero skin-in-the-game. I can either gain something or things remain the same (for me).
But at the same time, we as a community have to realize that this is not sustainable in the long run (take everything and give nothing back).
And we should protect our community from those who want to fan the flames by "s*it-talking" and bullying people/projects because they shared "more than enough" of their project but didn't share _absolutely everything_.
I also personally think that some "hobbyists friendly corporations" are very happy to "fan the flames" because it works in their favor. (Also let's get this straight, their cause might be aligned or born from the hobbyists, but they have bills to pay and mouths to feed. Absolutely nothing wrong with that but they are not poor mom and pop shops, they are corporations/companies that have to make money in order to survive).
Because if I'm one of these "hobbyist friendly corporations", I'm mostly making money from manufacturing (eval/dev boards). "Hey look, we made a Pico/Arduino/led/sensor eval board. Here are all the files that you need to make your own. Oh it's exactly the same as 500 other boards on the market from different shops, but this one has our company logo and custom standard (proprietary?) connector, and it's open! Keep in mind we shared everything because we care (although we probably mainly just copied somebody else's design)".
Now please keep in mind that I'm not saying that they are evil or anything like that, but at the same time... maybe they are also not all that altruistic and open hardware saints as they would like to portray themselves in our "open" world .
Unfortunately I've seen multiple projects and know people who burned out and gave up on "open hardware" and "open source" projects because vocal minority of people were "bullying" them and requesting to make the project meet their own definition of open.
And again, not because they want to contribute to that project in any shape or form. No, it was just because they saw the word "open" and this gave them the idea that it's their birth right to demand everything that was ever made or touched that project to be handed over...
We as a community have to realize and accept that "open" is a
very broad term. Door that is ajar is not closed, it's partially open, this is the definition. Is it ideal or would it not be better if the project was fully open? Absolutely! At least for me. But this also depends on the perspective and how much "skin-in-the-game"
you have...
But for the open hardware community, if there are no other options, partially open is still much better than fully closed, at least for me.
So I'm hoping that maybe (one day) we as the community can agree that "open" is an acceptable broad term that can be used for describing a project and that "open" does not imply "fully open", as much as a lot of us would love that to be the case.