"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

"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." I did not refer race. I am not ignoring but I am alerting that them may be BETTER served with cultures that conform with their ideologies and aptitudes. Why create a cultural shock? Why make the person struggle to be accepted? How many generations for me to be considered "japanese"? Or I would force japanese to me consider one of them?