The fear comes from the fact that Ebola is a ticking clock, accompanied by sweating, vomitting, and lightheadedness. That's an incredibly unpleasant, uncomfortable way to die, and it's still one of the best ways to. So first worlders have this idea of an apocalyptic, full-scale desertation of human societal structures and complete economical collapse in mind, whereas the actual results of, say, a 100 people getting Ebola in Western Europe or America would be bad and most of them would die, but not nearly at the level their imaginations are setting.
I think some people just aren't very well educated on the subject.