Note: I am not a lawyer, this is not legal advice.
In the EU, reverse engineering is allowed by law if the reason for doing so is interoperability by the one who owns a license to the product in question.
"The authorisation of the rightholder shall not be required where reproduction of the code and translation of its form within the meaning of points (a) and (b) of Article 4(1) are indispensable to obtain the information necessary to achieve the interoperability of an independently created computer program with other programs, provided that the following conditions are met:
(a) those acts are performed by the licensee or by another person having a right to use a copy of a program, or on their behalf by a person authorised to do so;
(b) the information necessary to achieve interoperability has not previously been readily available to the persons referred to in point (a); and
(c) those acts are confined to the parts of the original program which are necessary in order to achieve interoperability."
Luckily Nintendo (Shadowrun is still some years away, when Ninsonmicro determines what is legal and what isn't) is not the authority to determine if something is illegal or not. But of course they are entitled to their own opinion.
Here in France, as far as I know I have a right to private copy, which I pay for through a specific tax whenever I buy storage. I can rip my DVDs, Blu-rays, or even Nintendo Switch cartridges or hard drive, perfectly legally, even if it means cracking open the thing and circumvent stuff. It's awfully less convenient than downloading the stuff, but it is legal. Or at least it was 20 years ago, but I'm not aware of any change on that front.
Now there should be some ground rule. When you buy something, it's supposed to be yours, and you should be allowed to do what you want with it, especially studying it and sharing the results of your study. Any rule that allows some big corporation to retain power over something that's supposed to be yours is serious overreach and should be shut down.
Now Nintendo does have a big problem here: without the exclusivity of their form factor (which is arguably difficult to improve upon[1]), all they have left is the exclusivity of their game library.
In Sweden it was like that, but after some prodding and patting by "market forces" on the politicians it's no longer legal, but the tax is still there.
TL;DR: it's more complicated than I thought. First, the law was introduced in 2006, so before it, circumventing DRM and publishing how to do it was not a crime. (Of course, publishing copyrighted works with no proper authorisation was already a crime, regardless of DRM.)
Then for a brief time, circumventing DRM was outlawed. But fear of foreign monopolies (most notably Microsoft) and free software lobbying eventually had those articles amended, effectively exempting research and free software from any sanction. The exact limits of the current law are still fuzzy, but it seems pretty clear that using VLC to make copy of a DVD I own is 100% legal in France.
Are they really rare? I have an older switch that is easily hackable and can’t be blocked due to it being a hardware vulnerability but I have never bothered to hack it as I just don’t know if it is worth it. Not sure if you can continue to play online once hacked and I assume once hacked play pirated games as why else hack it. But I haven’t pirated games in a long time I wonder if it is worth it. What the switch really needs is a messaging app maybe hacked switches can do that idk.
Edit: Awesome - great to know!