You'd have a huge gas guzzler, requiring huge complement of seamen (huhuhuh), that's only good for one job, NGFS. It's not stealthy, has no sonar, and doesn't handle helicopters.
It does handle helos, who cares if it's stealthy, and they have more than one use.
NGFS is one. Fleet command/flag is another. Surface action is still a possibility, albeit slim, but it's still unmatched in that role.
What can a Zumwalt do, other than stealth, that an Iowa can't do better? Nothing. Yeah, there's less crew. Okay, and?
Missiles? Both have 'em.
Guns? Battleship wins.
Armor? Battleship wins.
Speed? Battleship wins, they're the fastest capital ships in the world, including the carriers.
Crew? Zumwalt has less, if that's a concern. There were no problems staffing the BB's, though.
No ship is as popular or as intimidating as a Battleship. We should have them active and a couple touring the world's ports just for that reason alone.
Hell, during the first Desert Storm, one of them made a port call in one country and they were so impressed they offered to pay the operating costs if we'd keep one active and base it there.
If you go through it role-by-role, the Battleship comes out ahead.
There's no arguing it, it's fact. And the CNO admitted to one of the professionals on the military boards who debated him about it awhile back that the Battleships were a better option, but his statement was "they didn't represent the image today's Navy wants".
In-between the lines, that means "we want shiny new things". That's where the money is.
Meanwhile, the Air Force is continually modifying and servicing and keeping the 60+ year old B-52 flying, and even today, just like the Battleships, it has no equal in the world.