Shane on 01 April 2007
The simple answer is that Wii Play/Sports are still from Nintendo. From a marketing perspective, the Wii line of games offers two things Zelda doesn't. When you advertise the games, you're automatically advertising the system because the name is the same, and the games also really show off what makes Wii different (with Zelda, the Wii features are just an afterthought).
Essay Pro