Both my maternal and paternal grandparents were immigrants. They became productive members of the American society, learned the language from their children who learned it at school, and became American citizens. They had strong work ethics which they passed on to their children. Their descendants served in the military and worked in white collar and blue collar jobs. They were proud to call America home.
Today's immigrants are no different - they want a better life, and they want their children to have a better life. America should not discriminate on those who want to start a new life, attend school, or have their family here. Today's immigrants or their descendants may become inventors, doctors, nurses, teachers, professors, farmers, business owners, etc. By turning them away, America is denying their dreams and possibly America's own prosperity.
Update: This issue is not about illegal immigrants, it is about those who have already been vetted, issued green cards an/or visa. Many of the individuals who have bee denied entry for "extreme vetting" have already been vetted and have already been in America. Many currently have jobs or are students and researchers at various universities. If you support the Executive Order have you considered that other world leaders called the White House to educate the President and his staff about the Geneva Convention? Have you considered if you leave the country, that YOU may be denied entry?