Hammer-fired guns have a similar issue if you drop them directly on the hammer (or on parts that can move the hammer) when the hammer is cocked. When the hammer is not cocked, there's no available energy in the firing mechanism to discharge the gun. Striker fired guns are effectively in the cocked state at rest, though. In a "cocked and locked" state, you would need the drop to disengage or overcome the safety, not just the normal trigger mechanism.