Well, I think people at the time were very disappointed because the graphical jump between N64 and Gamecube was huge and people were dying to see the next Ocarina of Time like game with the power of the Gamecube behind it. I myself was sad at first about not having a game like that... we did eventually which was Twilight Princess. Twilight Princess was not quite the legendary game that Ocarina was, but it was still pretty good.
Wind Waker is truly a fantastic game though. Once you get past the expectation of a new Ocarina of Time and simply take it for it's own game, it's amazing. The feeling of sailing that incredible sea with the music that never seems to get old is breathtaking. Wind Waker really gives you the sense of adventure. It's use of cel-shading is quite impressive and the sea was quite an achievement regarding the seamless loading and rendering.
I believe that a lot of people have come around to it in more recent years. Either way, the experience of playing that game is energizing to say the least.