The reason why TPHD doesn't 'look as good' as Wind Waker's is really a matter of art style. Wind Waker is simplistic, which made it easier to give the HD treatment and it really shows. TP on the other hand is more realistic and far more detailed, thus everything in the game was very refined, down to every little nook and cranny in even the smallest things, like symbols on the walls, textures on characters' clothes, and the extra amount of detail on midna's head piece. You have to look closely at everything in comparison to the Wii version, and it shows quite a bit.
Considering how much there was to touch up on TP, it would take so much more work than WW.
Dance my pretties!
The Official Art Thread - The Official Manga Thread - The Official Starbound Thread
