The purpose of the Excel Class ships is to differentiate itself from the rest of the current Carnival fleet and make the ship a little more similar to what the latest offerings are currently available from their primary competition from RCI, NCL and MSC.
The new Golden Jubilee bar area on the Celebration gives a nod to Farcus and the impact he had with carnival back in the day. There is no reason to come out with a brand new state of the art ship that looks like one of his outdated designs. It's time for Carnival and their new younger CEO to move forward, not backward.