No, I'm saying phantom hits are not part of game design. You can't call something bad game design if it's not part of the design phase; they're intentional, but not part of game design.
Again, phantom hits exist because of the way Melee handles damage calculations causing the effect of taking damage without flinching when you hit the edge of a hurtbox with a hitbox, but do not actually enter the hurtbox. The game thinks it's a hit, but because it's on that boundary, it just cuts the values a bit. Phantom hits are failsafe measures to use in case the situation occurs. Intentional, but not an explicit mechanic of the game.