For Alderney it's more a question if it was the hen or the egg that came first. Demografically Alderney had in the 2013 census only half as many 0-14 year old compared with the UK average in 2011 and almost twice as many 65+. Looking deeper in to the Alderney census it is very clear that families with children have moved from the island since the turn of the century and left behind an even older population. I'm guessing you will the same happening to the other Channel Islands as well as for the Isles of Scilly and may be other more and less remote islands up along the west coast of Britain.
Is it higher demand for travel that is not met or has it become that more difficult to earn enough money to maintain a good life at such a remote location the last years?