Madrat, you're right, it is expensive to keep a battlewagon active, but there is no ship in the world that packs as much power or offers anywhere near the protection that a battleship does.
What happens when we have to land the Marines on a hostile beach and they need fire support? Where will it come from? How many 5" or 6" pop guns do some of our modern ships have now....1? 2?
Then what happens when the enemy shoots missiles at the ships supporting the landing? If a missle hits one of our modern ships, it's out of action and maybe sinks.
Lob a few Exocets at the Wisconsin and if a couple get through, no big deal. They can't sink a battleship with missles. They can tear up some of the superstructure, hamper communications, but they can't sink it and they can't stop the guns from firing.
That's why I'm glad the Wisconsin and the Iowa are kept in the highest state of inactive reserve....all the interior spaces are shut off and kept dehumidified...in case they need to be called up again.
I think it would take 6 months to get one ready, so if you hear that they've decided to reactivate one or both, look for something serious to happen in that time frame.