Wii U Gamecube Controller Adapter only Compatible with Super Smash Bros for Wii U

[HigHurtenflurst]

brute said:
This is disappointing, but what confuses me is that why it needs to be clarified that it doesn't work with Wii? Wii already has slots for GameCube remotes, am I missing something here?

The more recent Wii consoles don't have GC controller slots. (I think it was 2012 onwards)