It's not a personal attack to say that you have a definite horse that you like to speak on ("race", as nebulous and weird as that is). Above you have reframed more or less the same thing as a culture issue, which has been widely discussed and is currently popularly mitigated with education. We can see this works in practice.

What more do you want? Justifications for why people move out of their cultural frame to a different one? Perhaps they value more rights for women (the middle east is out then). Perhaps they enjoy a peaceful environment (again, the middle east is out). There are so, so many reasons someone might move away from their reference frame. Some don't apply to the middle east. Some don't apply to Asia. But they definitely apply to someone, somewhere.

I simply cannot believe you have not thought of this, but to construct this narrative you must ignore these realities for why people flee their own environment in favour of a new (much more uncertain) one.