What are the tradeoffs of open carrier gun mounts?

Is there an advantage to unenclosed main gun mounts on aircraft carriers?

They reduce topweight and ease escape, while an enclosed mount is worthwhile only if it offers real protection.

Open gun mounts reduce topweight on a carrier, where every high-mounted ton competes with aviation facilities and stability. They also give a crew more ways to escape a dropped round, fire, or local accident. Enclosure becomes worthwhile when it provides armor or meaningful splinter protection. A thin box can instead trap the gun crew when hit, so protection must justify both its weight and its restricted exits.