I can't believe I've never seen this topic. I saw a guest look at it and I said to myself, have I seen it? Tradition is a pretty good guess. But I'd like to believe that Sakurai loves screwing us. JK.
I have to ask the same question, but I ask something more, why do newly introduced characters not become hidden characters? In Melee, they introduced Zelda (Sheik), Bowser, Peach and Ice Climbers as starters and these people maintained their starter status in Brawl. Captain Falcon and Ness did become starters but in brawl, they became hidden again. Luigi and Jigglypuff have retained their hidden status ever since. In Brawl, they introduced Wario, Meta Knight, Pit, ZSS, Ike, PT, Diddy, MK, Lucas, Dedede & Olimar.
What is weird is that Ike, Lucas, Wario and PT are newcomer starters while Marth, Ness, Luigi and Jigglypuff are unlockable veterans. It's actually weird that the newbies become starters while those that been there since 1999/2001 are still unlockable by 2008.
Anyway, you can see I have no clue. Let's just say Sakurai keeps them secret so that we may long for them while the starters are given early exposure.
