There's always been a lot of excitement about the idea of a graphically rich, mature Zelda game. Both the Gamecube and Wii U used a Zelda tech demo to show off their capabilities, but what the Gamecube eventually got wasn't a realistic, dark Zelda game. It was a light, fun, cel-shaded adventure on the high seas. And it annoyed a lot of people – all of whom had missed the point.
A lot of Shigeru Miyamoto's games are his way of distilling an experience to its most enjoyable. The story of Zelda's inception is that in his youth he explored the woods near his Kyoto home and stumbled across caves, which he would explore, presumably filled with bats that chased him and spiders that seemed much larger than they were to a child. The idea of the Zelda games is to bring this particular feeling of child-like gumption to anyone and everyone – wrapped around a narrative of saving the world, naturally.
The 3D Zelda games haven't generally stuck true to this spirit. For me personally, even Ocarina of Time isn't really a proper Zelda game. The sense of wonder in exploration is the idea of the completely unknown – to go down into a cave, fight your way through and discover something that no one has seen in hundreds of years, if ever. Ocarina of Time has a sense of exploration, but the sense of discovery is only one of your own – other people have already got to just about every part of the world, it's only you who's seeing it for the first time. This is also true of Twilight Princess, though that does at least have the Twilight realm to claim as unexplored (except that it's pretty much a mirror of the regular realm, so doesn't count).
Wind Waker, on the other hand, is the story of an entire lost world. The idea of discovering an unexplored island immediately adds to the sense of wonder and intrepid valour, but what you find on these islands also often hints at what was lost. It's clear that nearly everyone left in the world is oblivious to the kingdom you begin to explore – these discoveries are all your own.
(Skyward Sword takes a wander in the direction of discovery, but the way it restricts you to little hub areas pulled it back away from that for me.)
And in Wind Waker, you do that discovering with a comically emotive cartoon avatar, partnered with his talking dragon/lion ship. It's just the perfect tone for filtering adventure through the lens of childish exuberance. I think the heart of Zelda is not the mature fantasy epic that began with Ocarina and is now desired by a large portion of the fanbase for every game. It shouldn't be Lord of the Rings – it should be The Hobbit.
When the HD remake of Wind Waker was announced for Wii U, the console became a must-buy for me. I have played it over and over in the past, and I will again. I can imagine young Shigeru Miyamoto clambering into caves, creating stories of the dangers and rewards within, and he doesn't look like the Link of Twilight Princess or even young Link in Ocarina. He looks like cartoon Link, with a grin from ear to ear, confiding in his trusty boat companion.