Things aren't just black and white. London and Paris, also Frankfurt are partially hub airports. Many long-distance flights from Europe will relay via those airports. Additionally you have direct flights. And with the raising passenger counts, there is a need for large airplanes on point-to-point connections too. Of course only on the important ones, but there is a need. A shortage in runway capacity also limits the amount of flights you can have from an airport, so to raise the capacity, you have to go bigger too. Right now, there is obviously no large demand for the A380, but I could see how that changes again - especially once the 747s in use got retired.