I think you really have to be cautious about where the news is coming from these days, and if the whole story is being told. For example, did the Canadian woman reportedly turned away have a second citizenship? and therefore a second passport from one of the countries on the restricted list?

One random post on the internet suddenly becomes a major news story with unnamed sources. It's very hard to know what to trust. Seems everyone has a not so hidden agenda.
Rights of citizens and non citizens differ in every country. US is no different. And it goes both ways. People from the small company where my sister works have been denied entry into Canada many times, and were unable to service their company's machinery that Canadian businesses purchased. Every country has the right to control who crosses their borders, or it's not a country.