Or, because proper precautions and first-world infrastructure has a way of stopping Ebola outbreaks in their tracks (notice how it didn't spread in any of the other first-world countries that treated people during the outbreak last year?)
Recall the Obama admin bringing people straight from the hot zone in.
Victims were brought in for treatment in level 4 biocontainment hospitals, which were specially built for things like ebola and similar diseases.
Others coming in from the affected areas (not "straight" - there were not any direct flights from the affected countries to the U.S., before or during the outbreak) were screened.
Will you host Ebola exposure victims in your house?
If not, why not?