FCD had Drephen/Darkrain/Vidjo in the Top 8, so it's not like we've never had players at the top level, and Drephen/Darkrain both won some majorly stacked regionals outside the MW, so it's kind of silly to say there's never been a top-top level player from the MW. But no, Midwest never pulled down a national champ.
Think it's kind of ridiculous to attribute that to stages, though. You guys seem to believe that it's an either/or proposition, but the inclusion of stages has little to do with one's desire to improve technically and more to do with what you philosophically believe about Melee as a game. When I practice technical skill, it's always on neutral stages because it does create a "safe" environment for perfecting those skills, but that doesn't mean that's the whole extent of the game. It's just a piece.
We just always tried to let Melee be it's own thing, you know? If ICs suck on half of the stages, then maybe they're not a good character? If we were trying to balance the game in 2006, maybe we would've banned the plat stages that gave Fox too much of an advantage over Peach to give Peach an advantage? You can't force balance, because the game is always changing and inherently unbalanced, and balance is pretty much an opinion since there's no actual data that can separate player skill. Well, that was always our philosophy, anyway.
Wanting more stages != terrible player. That's a horrendous conclusion to make and would pretty much validate every internet stereotype that gives smashboards and tournament players a bad name.
Then again, maybe ya'll don't care.