Legitimate developers and enthusiasts only use keys extracted from their personal consoles.
While production keys unlock the general encryption layers, title keys are specific to individual games. Every game, patch, and DLC has its own unique title key. This key decrypts the specific Content Metadata (CNMT) and Network Content Archive (NCA) files that make up a retail game. How Switch Decryption Works nintendo switch decryption keys
Nintendo's DMCA takedown request specifically noted that the Lockpick tools, combined with a modified Switch, let users grab the cryptographic keys from their own Switch and use them on "systems without Nintendo's Console TPMs" to play "pirated versions of Nintendo's copyright-protected game software". This ability to circumvent the console's native protections is what transforms legitimate key extraction for personal backup purposes into a tool for large-scale copyright infringement. This key decrypts the specific Content Metadata (CNMT)
This argument has been used to justify takedown requests against: This argument has been used to justify takedown
"The keys are the difference between a game surviving and a game dying," says one digital archivist who asked to remain anonymous. "We aren't trying to steal from Nintendo. We are trying to ensure that the history of this medium isn't locked away forever behind a corporate paywall that will eventually shut down."