Ok, so let's put this into perspective:
Melee--Fox v Mario. Who wins? Fox
now skilled fox v skilled mario. Who wins? Mario.
Don't believe me? Then you really don't understand each character's potential.
I'm not saying he wins everytime, and if both players are equally skilled (which rarely happens and is almost impossible to determine since no 2 players are alike) Fox does have a better chance. If that's what these tiers are, then i can agree with that. But does this mean tiers should decide which character someone plays? No, and that's what's frustrating me. People don't have any sort of reason to tell you that you cannot play a mid or low tier because they will lose. If i want to do a tournament with Pikachu the only thing stopping me is getting good with pikachu. Once i'm good with him, all those 'pro' meta knights wont stand a chance.
So your precious tiers are more like minor guidelines more than anything. If this tier was to govern the way people played Brawl, then every tom nick and harry would be playing Meta Knight, Snake, Wario, Falco, Diddy Kong, and Dedede. And Kirby loses to Dedede? That's just sad and totally inaccurate.