Agreed. A crowbar model already exists in the game, even if as an Easter egg. Ast has a point with durability too.
Zero's stores though... meh. There are all sorts of hardware stores around the map which R* likely intended to be usable in beta. We could potentially add those back in in the update that will introduce crowbars. Not just for the crowbars though, I'd like to see more melee weapons, tools, and other items featured there that are currently found in Ammu-Nations, Zero's stores, or 24/7's. Should be similar to how they did it in Vice City. Frankly, it's even possible to introduce custom melee weapons, even though that's more of a challenge under 0.3.7 than it is under 0.3DL or OMP.