Because Fire Support for US Marines is a bad thing

Marines get the short end of the stick on Capitol Hill says Novak

The Navy has a love affair with carriers. Always have. And carriers are great. Unless the weather is bad. But since Marines are a little bit like the US Postal Service (Rain,Sleet or Snow) They'd like to keep the battleships for fire support. Because God forbid you keep the ability to shell the enemy with 460 projectiles in nine minutes. And when we say projectiles, think "exploding volvos" (a concept our current enemies can understand all to well.)

Fortunately We here at DKRepublic have a solution. What we need is a vessel which can fulfill both roles admirably. Why have two ships, when one will fulfill both needs?

I've submitted a detailed sketch of my proposal to the Pentagon