You know, our biggest threat from persons traveling to this country is terrorism - and as luck would have it, the terrorists who would do us harm by incredible coincidence happen to hail from majority Muslim nations - a little less than a third of all the world's nations.
So it kind of goes without saying that ANY nation where we wish to curtail travel from is going to be majority Muslim. One of the biggest complaints - a stupid one, but the biggest - is - why don't we ban people from Egypt, or Saudi, or Nigeria, or Indonesia? Oh really? How come you DIDN'T mention China, or India or Germany or France? And among other reasons, it's because they're not exporting terrorism. We're not at threat from crazy Japanese who want to blow us up or run us down with a car. People bring UP Egypt or Saudi in a dumb response but they are pointing out what we all know - we are threatened by radical Muslims.
We do not require improvement on our vetting process from these nations - because they are already cooperating with us since 9/11. These other nations - most of them - are not. So it is incumbent on US to take a break to improve the process.
What is so goddamned horrible about making someone from say, Somalia wait an extra sixty days? It takes almost that long for me to obtain a visa for just about anywhere I travel.