The stolen Nintendo cartridge code is the major piracy part. It's not just about the games (that's a separate piracy). It makes no sense for people to argue "anti-piracy" but then turn around and install games to their SD cards off the HDD, piracy is piracy.
Running games off HDD in SXOX involved stolen cartridge code + stolen games.
Running games off SD in Atmosphere only involves installing stolen "borrowed" games using a third party homebrew app. (In b4 someone tries to argue "I rip my own cartridges so it's not piracy", that's not the topic.)