Passenger ships need to earn their living today. Unlike the "good old days" they are not maintaining a vital communication link and governments no longer provided construction finance, fat mail contracts, emigrant contracts or outright operating subsidies to keep liners at sea.
Unlike any of her predecessors throughout the last century, QM2 has been designed and built to provide a profitable, unsubsidised Transatlantic service. She has also been designed to carry out this work for the next 40 years. Her standard of seakeeping and the quality of her accommodation are both far higher than any previous Transatlantic liner. It is the exact opposite of "so anything goes". Only the very best will do, to meet this requirement.
Of course QM2 also needs to make a profit. She can only do this by attracting passengers on holiday by offering a magnificent service at a competitive price. Most of the Atlantic liners of the past were unable to make a commercial profit even though there was no other way of making the crossing.
Still ugly as sin though-- and the stern looks like it was modelled in the same way ,and by the same person ,as the head in the Lionel Richie video for "Hello"!!!!!-- bears no resemblance to any shaped stern I ever saw before.
It is a Constanzi stern, as used in the Italian built liners Oceanic and Eugenio C. It is a highly efficient design, which combines the speed enhancing properties of a transom stern with the seakeeping qualities of a cruiser stern. In QM2 it has been developed from the twin screw configuration of the Italian ships into a shape that is optimised for four pods.