They couldn't figure out how to jailbreak the Wii U back then, but just last year or back, people finally had a way to have homebrew on Wii U mode (and the PS4 is just following the Wii U's footsteps in the hacking scene). Around the same time, back in late 2015, people got VC injects working on Loadiine 4.0, and later its GX2 fork, and now that IOSUCFW is released we can be able to convert them to installable format and play them on our SysNAND/RedNAND without Loadiine; just ordinary signature patching like the 3DS.