It's not about the "middle east region" or even Qatar the country ... show me one other employer in the region that has such an insane policy ... it's about one megalomaniac psychopath who happens to be the CEO of that particular airline.
I really, honestly believe he just does this kind of sh!t (and all the other million crazy little rules) just because he can, because he gets off on holding total God power over his employees, and making them beg to him personally for such a basic human right as marrying. He needs psychiatric help man.
He can and does refuse the marriage permission as well, pilots as well as cabin crew, in the time I was there, one very senior and very nice guy A320 captain from Croatia got terminated for marrying against AAB's permission