This is 100% not a reference but a dumb Disney decision
If Kirby were lore accurate he also wouldn't be able to wield Shulk's Monado, or Lucina's Parallel Falchion, or Chrom's Falchion, Or Roy's Binding Blade, or Corrin's Yato, Or Byleth's Failnaught, Or Pyra and Mythra's Swords