It is interesting to read all these 'horrible' experiences in THY. Please allow me to state a different opinion and describe more pleasant experiences.
For your reference I am not Turkish. Coming in THY was a good experience for me. My previous job was in a north European company and was terrible, not even close to these 'high European standards' .
Starting from the assessment in Turkey I found it very professional. The simulator checking was tough. The instructor was fair in my opinion, he failed the captain who was flying with me.
Flying on the line is a good experience. Most captains are friendly and professional (including the ex military captains), I did not face any problems at all. Occasionally one or two captains were using Turkish language when talking with cabin crews in the aircraft or in the hotel but this did not bother me much.
In general I think the work environment is good and I find Turkish people very warm, friendly and willing to help if you have any problem. If I would think in future to leave for another company it would be only for a quicker command upgrade ( in THY upgrade can take long time) or a higher salary, otherwise there is no reason for me to consider leaving.