But the fact is Nintendo is one of the most litigious of the copyright monopolists, a class of rent seekers who have systematically robbed us of our fair use and public domain rights.
There is no reason to believe they'd leave you alone if you refrained from hacking their latest games and consoles. In fact, they have repeatedly proved that they won't do that.
They have already made their fortunes many times over. They have already been more than adequately rewarded for their works. Even the Game Cube and its games are already old enough that they should be in the public domain, but Nintendo couldn't care less, they will absolutely hoard even NES games from the 80s, and they will absolutely reserve the right to sell you that exact same Mario ROM over and over again until the end of time. You and I will be dead and buried before this stuff enters the public domain. If they ever do. Who's to say the trillion dollar industry won't buy laws, I mean lobby the government for yet another copyright extension?
I just can't deal with it anymore. I think people should radicalize, not play nice with these monopolist corporations. I seriously hope AI hammers in the final nail into the coffin of intellectual property.
Regardless, for previous generations included, work on emulators and hacking consoles happened when the console was still current, of course.
You can’t start the reverse engineering work only after the console is superseded, by then it is too late for preservation, especially with live service games.
It's true that Nintendo hasn't always sicced its lawyers on emulator developers for current gen - I'm fondly remembering the GBA era, when emulators based on leak dev kits started popping up before the console was even released - although that really only hurts matheusmoreira's point all the more; they're clearly OK with giving devs a fair amount of leeway. As for why that didn't apply to Ryujinx, it's hard to say, though my best guess is Nintendo was trying to get ahead of the "Yuzu alternative tears of the kingdom" Google searches.
This is a minor point, but I'll mention there really weren't any real NES or SNES emulators during their lifetime and yet they're among the most well-preserved consoles. Although sadly this did mean we lost quite a bit of Satellaview content, speaking of live services.