Serious question: why not all? What’s good for the goose is good for the gander, right? If this change improves the balance of strength and dex (and I’m not totally convinced it would, but giving this rule the benefit of the doubt), would it not be better to apply it to all weapons? And it’s not like it doesn’t make sense - no matter how bulky a weapon, coordination and agility are going to help you use it more it accurately, and no matter how light and agile the weapon, physical strength is going help put more mechanical force behind your strikes. Just seems like if you’re going to implement a change like this, you might as well implement it across the board.