I think just the fact that Wind Waker was something
different is what encouraged other companies to follow. It may have not initially received positive feedback, but it certainly stood out. By different, I mean not the typical surreal 3D/2D games. To true-to-heart fans, it doesn't matter how Zelda looks, they're still going to get it. And even non Zelda fans are praising the game's "seamless and fluid animation" now. And it's marketers' jobs to foresight these things before they're realized by the public. And that's why you see "out of thin air" all these cel shaded games following Wind Waker.
If you can't beat the competiton, follow it.
