Checked to see how many sailors man our carriers?
The combat radius for a 16" gun [full 16" not with a theoretical sabot] is only 22 to 24 miles.
That being said an Iowa makes for a relatively hard target, can carry a butt load of missiles and can I have been told can deliver as much ordinance via its 16" guns in 45 minutes as a carrier can deliver in 24 hours.
Big guns can be automated to a certain degree -- look up Des Moines class cruisers. Coming back? Probably not, in part because they have no sponsorship and partly because of the whole range limitation issue.
Aircraft carriers house squadrons of fighters, bombers, surveillance, control and anti-submarine aircraft, each aircraft capable of attacking or defending against multiple targets. No other vessel does that. I do think that they should look again at the Pykrete concept which was briefly explored during World War II, though.
http://en.wikipedia.org/wiki/Project_Habakkuk
I think that the US industrial base could not make a large caliber gun barrel these days. The “Iowa”-class gun barrels had a rated life of about 300 rounds (depending on the powder load and other factors). Now each ship was ordered with spare gun barrels and I think that there were even some turrets around for the cancelled “USS Kentucky”.
Then there’s the problem of the diminishing potency of the gunpowder charges. They would have to test-fire the 16” guns periodically to see how well the gun performed as the barrels wore and the powder aged.
So you begin to get the idea that even if the Iowa-class was everything its advocates hoped, it wasn’t going to be for all that long.
Virginia Class submarines can carry a lot of Tomahawks, especially when they extend their hulls.
Also, shells (and missiles) can be delivered in weather that aircraft could not fly in, and shells and missiles do not care if the target is ringed with SAMs.
The pendulum swings back and forth. Aircraft are currently supreme because they can drop bombs on distant targets, then come back to the carrier for more stuff to drop.
Things change when the enemy has effective anti-air defenses, and when sensors can detect "stealthed" aircraft.