Why wing ribs have diagonal struts
The diagonal struts are best to transfer shear. Imagine an upward pointing load at the nose. In order to get that load transferred to the fuselage, it first needs to be transferred to the wing spar. Imagine now that you hold the rib firmly in your right hand where the spar is and press the nose upward with your left hand. With parallel struts, the rib will have much less stiffness and the nose load will deform the rib easily. With the diagonal struts, the rib is much stiffer when that particular nose load is applied.