The UAE and SA should be on the list.
With that said, the U.S. is still open for business for hundreds of millions of Muslims and hundreds of millions of other people, so getting into the country isn't that hard.
ISIS has infiltrated operatives into the ranks of refugees. The prior administration suspended Iraqi visas for 6 months because of ONE guy, and the testimony of two other guys who were more likely just trying to get themselves off the hook. The historical and legal precedence and power for this temporary ban has been signed off on again and again by Dems et. al. numerous times, including numerous Dems who are still holding office. The Middle East is as eff'd up as it's ever been ISIS/ISIL, AQ, AQAP, AQ Libya, ISIS Libya, ISIS Sinai, they're not the same as the nation state sub actors like the PLO, Hamas and Hezbollah. The civil wars (with huge US involvement) in Libya and Syria and subsequent refugee crisis have only made the situation worse.