Which makes perfect sense - none of the previous producers have. Mostly, they've just used their stock characters and locations, and made a game that they thought would be fun out of them. There's a couple of games that qualify as 'direct sequels' (Ocarina -> Majora's, Wind Waker -> Hourglass) but even then, it doesn't benefit you much to have played the preceding one. Would be weird to try and twist the games into a chronology that strikes me mostly as 'fanon' anyway.