A good question!
Mainly sunshine, warmth, UV, Vitamin D, exercise, cheapness, a good exchange rate, possibly archaeological/cultural stuff - your Goreme pic was interesting - and bimbling and patching.
I've "done" S Turkey, plus Armenia, Georgia, Syria, Israel, Oman, however Kurdish Wheatear and Mongolian Finch (and Brown Fish Owl I spose) have eluded me. Bad time of year for both so may just get a cheap package. Used to enjoy a bit of skiing. Or there's the Laodicean Way to hike along. Maybe I'll visit in Spring too.. not sure yet. 👍