Was the 4.7-inch gun itself a poor anti-aircraft weapon?

Was the 4.7-inch gun itself a poor anti-aircraft weapon?

The gun could perform well against aircraft, but the mounts under discussion could not provide the high-angle coverage of a true dual-purpose installation.

The distinction is between a gun's performance and the angles through which its mounting can engage. The destroyer installations could fire at aircraft approaching at low angles. A true dual-purpose mount needed to cover roughly -5 to +80 degrees, including targets high above the ship.