I'm generally someone who likes to visit new and different places just for the sake of it, so I get you. Having said that, I've lived in Greece for 19 years now and I've only been to 11 of 33(?) Greek airports (and three of those were only on package tours when I was a kid living in the UK).

To visit more domestic airports quickly, I'd recommend taking ferries and buses between islands where you can. It's not as easy (or cheap!) as it used to be as most routes follow a single island "chain". For example, you could do Athens to Naxos in the morning, take the mid morning ferry to Paros then fly back to Athens by around 1pm. Then do the same somewhere else (Mykonos/Syros or Chios/Mytilene or Kos/Rhodes. Santorini transferring by ferry to Milos would probably work well with ferries too). There are very few inter-island flights (not counting Crete) but some do multi-stop such as those to Kassos and Karpathos. Outside Athens there's only really Thessaloniki that has some domestic flights to other airport (Heraklion, Chania, Corfu, maybe Rhodes or Kos) and maybe Heraklion (Alexandroupolis?). Many airports are well connected by bus, such as Thessaloniki, Kavala and Alandroupolis or Chania and Heraklion.

If doing this kind of thing, the domestic AegeanPass would probably work for you but I think it only applies to Aegean flights, not Olympic.