Boeingrestricted:
This new rule of 12hrs, if it's true (which I do not doubt) is, if I may speculate, just to suit them operationally.
Today you are practically forced to go flying when sick.
Your base is Istanbul, which on the short haul means both IST and SAW. A three hour drive between these two are not uncommon due to the insane traffic still, they are both considered as your home base. It's not uncommon that you start your duty on one airport and end it on the other one and have to spend alot of time going home.
Add to that, very dodgy rules regarding what's a standby, duty or not and it (at least for me) becomes apparent that they do not care about fatigue, health and rest however with the ever increasing traffic and shortage of crews, they for sure need more flexibility when it comes to rostering their crews.