I beg to differ, Cmdr.
There is a place for a ship sporting heavy caliber guns. Whether or not this has to be a battleship, is open for debate. It's only because we still have battleships that they've even been part of the discussion.
It has nothing to do with gunboat diplomacy, it's all about having a capability that no one else has, or which might be a better solution to a particular problem.
Marines and soldiers reuiring heavy, accurate fire support, at a moment's notice is a problem, even if we haven't hit a hostile beach since Inchon. Aircraft and helicopters are great, but they cannot go and do everything.
Another interesting ship that can be built to fill this role could be a monitor. Remember the Brits built the Abercrombie and Roberts in WWII for bombardment and they were very sucessful.