Of course every person has worth and dignity. But from a practical point of view, he said there are millions of migrant children every year, and it's just not possible for developed nations to absorb this number annually.
He also called upon us as individuals to help. My wife and I are not in a financial position to take in a migrant family, but you certainly are. Do you currently have a migrant family living with you? Are you personally paying for hotel rooms for them?
Finally, I read your link against my previous policy, so as a courtesy, I'm linking again to Dr. Risch's paper so you can, in intellectual honesty, return the favor.
Link: Dr Risch paper