Organic growth is far superior to “throw a load of routes at it and see what sticks.” A company who expands on the basis of using data to figure out where demand is will make better, more informed and hopefully more sustainable investment decisions which ultimately benefits everyone employed by the airlines, airport and the ancillary businesses linked to both.
Also, what is the opportunity cost of taking those aircraft off other routes? If an airline was to show up tomorrow with ten airframes and forty routes you need to question what has this company been doing with their assets that they feel confident that trying them in an untested market is likely to give them more return than what they have been currently generating.
Additionally there is a lot of work that needs to be done around schedule to make sure that the aircraft are being used in an efficient manner. Arrival and departure slots, especially at holiday destinations during peak season are very valuable to a company and need to utilised to the company’s maximum benefit. To give capacity to these destinations ex SOU means that a company has had to reduce capacity on an existing route or apply for additional slots. Airlines do lots of market research before launching a route but the proof of the pudding is in the eating and if demand is high and yield is strong then it would be reasonable to expect more long term investment and growth.