I have known quite a few immigrants in my life, and they do not want to immigrate to West Virginia or Idaho. Jewish Russians were not dreaming of a day they could live in Idaho. Chinese PHDs are not desperately trying to relocate to West Virginia. These people want to come to our big cities. You try to make that sound bad, but it is what keeps these big cities alive.
By the way, while California was growing by 6.1%, do you know how much West Virginia was growing? -3.3%. They were actually losing population as people desperately tried to leave. The sad truth is while people could make better money if they left West Virginia, they often just cannot afford to relocate. They are trapped in poverty there.