They keep winning the cases themselves in courts very much rigged in their favor, sure, but for each headline, they risk alienating more gamers who don't appreciate them bullying comparatively tiny sites who are just providing games that Nintendo themselves refuse to sell.
Them issuing C&D after C&D costs their legal team time and money they could be using to, idk, trademark new IPs or license third parties for libraries and music. It also hurts their PR.
They keep paying money for attorneys and court proceedings but don't get anything in return, since the code is out there and will just be shared again by someone else. Hence: whack-a-mole
A company like Nintendo definitely has a law firm on retainer. They're paying them whether or not they're being used. There's no waste of money happening by going after "IP violations."
A waste of time and energy, perhaps. But the lawyers are getting the same money whether they do this or nothing at all.
Having the keys on their official website to download seems a bit risky. We don't provide the keys on github, so we will fight the DMCA, but use this media fire link to download them...
Yuzi provided means to grab keys and firmware from a Switch console, which seems to be a big red flag and a reason why Nintendo went after them. Sudachi also has guides and download links for decryption keys and Switch firmware. From what I can see ryujinx only provides some guides on how to get the keys from a Switch but no apparent download links or "shortcuts"
Besides, we should not be pointing fingers at emulator devs. Companies are not your friend, we're just a means to profit for them.
It's also suspected that Yuzu was not "clean room" reversed engineered and built on code that they shouldn't have had access to, which will allow Nintendo to pull down any fork of Yuzu but not Ryujinx.