The WHO and related organizations have an unbelievably large data pool when it comes to the spread of diseases. Between historical records and computer simulations, they know what the most likely outcome for most courses of action is. If ebola spread easily and was airborne, yes, they would probably shut down airports in affected regions, much like with SARS. But ebola is not airborne, and it does not spread easily.
Much as you would like to think otherwise, no, you do not know more about the spread of disease than the experts who have devoted their lives to studying it.