One argument is that positive externalities, such as higher growth due to global mobility, outweigh the microeconomic losses and justify continuing government intervention. A historically high level of government intervention in the airline industry can be seen as part of a wider political consensus on strategic forms of transport, such as highways and railways, both of which receive public funding in most parts of the world. Although many countries continue to operate state-owned or parastatal airlines, many large airlines today are privately owned and are therefore governed by microeconomic principles to maximize shareholder profit.
Nine weeks in Greece is a dream itinerary it certainly gives you lots of flexibility. As you seem to have Athens and the Peloponnese sorted, you just need to sort out your five weeks on the islands. What you need to realize, however, is that the islands are not all mutually interconnected, but rather they are ‘grouped’ – both administratively and from the point of view of transport routes. Here are the main groups.
A complicating factor is that of origin-destination control ("O&D control"). Someone purchasing a ticket from Melbourne to Sydney (as an example) for A$200 is competing with someone else who wants to fly Melbourne to Los Angeles through Sydney on the same flight, and who is willing to pay A$1400. Should the airline prefer the $1400 passenger, or the $200 passenger plus a possible Sydney-Los Angeles passenger willing to pay $1300? Airlines have to make hundreds of thousands of similar pricing decisions daily.