Convenience?!? This is the least-well thought out porting decision for this game.
For those who don't know, this game follows the traditional Zelda path of having three save slots in the game. On the gamecube, this is not a problem -- when the fourth person wants to play, you can just swap in a new memory card.
AFAICT, on the Wii it is impossible for more than 3 people to have Zelda save games. For goodness sake, this is a 4 person console system! In my house, I'm number 6 in line for a slot, and I don't think anyone is finishing their game any time soon.