Perhaps not MarkD however a number of airlines have tried and failed in Greece.
The only truly succesful one is Aegean who purchased Air Greece the year it started its scheduled services to enable quicker growth and then merged with Cronus Airlines two years after starting up.
Cretan Airlines lasted only two years and Hellasjet also only lasted two although the latter is trying to make a comeback this year.
SkyExpress are making a small niche market using Jetstreams on small interisland services but stay well clear of Athens.
Olympic provide a very valuable service to the islands and realistically if they go, I cannot see Aegean picking up routes such as Paros, Naxos or Syros.
I think it is important that Olympic survive in order to keep these routes flying as otherwise many islands will lose their transport connection as other airlines will not pick them up.