Unfortunatey it is just another case of risks and rewards. Such destinations are a goldmine for the few operators willing to take the chance, because the only people flying there need to, and usually have veeery deep pockets (or rather the organisation sending them). From such revenues it is possible to pay both the insurance premiums and the exrta risk pay to crew. And if there is a fat reward dangling, there will alays be a few who will say yes. Does Air America ring a bell to anyone ... ?
PS: I don't know if TK actually pays extra to crew on these flights (Beyrut not necessarily, but Mogadishu, Benghasi, Sebha, etc), would anyone know ?