Except the cartridge is not writable. (or at least, should not be writable.) It also remains to be seen if multiple titles can be stored in the cartridge memory space. (It is functionally identical to having multiple games on a Wii-U disc.) The potential to have something like an R4 card for the Switch is interesting though, where the console thinks it is launching a single game, but is instead launching another launcher. Bear in mind though that many switch titles are HUUUUUUUUGE compared to the titles for the 3DS and pals. A 200gb card might hold what--- 4 titles?
No, if you are talking piracy here you want a USB loader, where you can have a several TB capacity device. A pirate flashcart would be useful mainly for bootleg game titles made by indie developers. (assuming a reliable way to run unsigned code on stock firmwares is discovered, or the signing keys are discovered.)
I could see a custom cartridge being used as a trojan horse to get access to the console using a game though. (Cartridge software uses a weakness to somehow execute, spoofs being some other title ID, and writes a savegame, then exits. User then inserts the vulnerable cartridge, starts, and loads the savegame for fun and profit.) It is far fetched, but I could see it happening.
The utility of the cartridge slot is pretty limited though. The USB port is totally where it's at on this thing if you are looking for piracy. I am mostly interested in playing modified titles, rather than pirated titles. (Skyrim + mods in my pocket bro, can you dig it?) From a technical standpoint, there is no effective difference, but from a philosophical standpoint they are black and white. To achieve my objective I need a dumper and loader, same as a pirate. The existence of the tools is not the sin, it is how you use them.
