Because Nintendo knows Americans hates Tingle. Tingle was in almost all of the Zelda games after Majora's Mask, but American fans didn't like his looks, his personality, and his over-priced translations of the Triforce Hunt in Wind Waker. Nintendo decided to stop putting Tingle after Minish Cap. Hence they made Purlo for Twilight Princess and turned Tingle into somewhat of a cameo in future Zelda games like Skyward Sword and Spirit Tracks.
I happen to like Tingle. He's really really wierd, but quirky characters like him make the Zelda series unique. I would have liked to have seen him in SS. I guess I'm in a minority of opinion though, as it's clear a lot of people despise him.
And btw, as others have said; Tingle's first appearence was in Majora's Mask, not Ocarina of Time.
where would he be? it would make no sence for tingle to be on the surface because Impa is the only human on the ground and she has an excuse, and he wouldn't fit in with the skylofians. i just couldn't see him in SS