Admittedly the CAA looks with disdain on the trend as likely to cause market distortion. But everyone has to fight their own corner and even the mighty City of London Corporation was not above commissioning Oxford Economic Forecasting to study the impact or airports on the growth of its banking and financial services.
One of the points to emerge from this study was that 75% of "City"(i.e. banking and other financial related business) air journeys went to just 20 destinations. And only two of these were in the USA with five being in the UK (headed by Edinburgh but including Liverpool). Frankfurt and Dublin were other favoured destinations.
There is even now talk of airports becoming "virtual" - using their skills to combine the timetables and operations of several airlines. This would mean passengers being told at short notice that their takeoff point was Liverpool and not Manchester and vice versa.
They might mind at first but get used to it. Look at the way smoking has been abolished on airlines. The passengers as well as the airlines are on a learning curve.