It took FR a long time to get into Greece, but they are in there now (whatever economic issues, people can still come in to spend money, but many people will avoid Athens, where FR don't fly anyway).
So is Turkey just a matter of time, or is there a genuinely significant obstacle?
They may be in Greece now but they are closing all Rhodes and Kos from first week in October over marketing support, I can see others being closed fairly quickly as well as Greece can't afford FR.