>>509802956 (OP)
They were never "needed" in the first place. They were brought in to destroy the nations they immigrated to, not to benefit them. Your question is built on a false premise.
Also, India and Iran have plenty of need for high-skilled, highly-intelligent labor, so we'd be robbing those countries of their potential if we took those people away from them. I'm such a good humanitarian, I can't countenance that, so leave those people in their own countries so they can help their own kind to develop.