I'm not sure what this has to do with the Dublin Airport Authority Tom? Probably more to do with the two tier performance of the Irish Economy and also due to the fact that Cork seems to be unable to attract enough inbound visitors and so is over dependant on Cork people flying out of their local airport.
The number of long haul flights available from Dublin to America and the MIddle East may also be affecting the numbers travelling long haul from Cork via LHR.