True, or even longer than 21. But most cases become symptomatic after 5-6 days. However those stats come from Africa and it might be longer for first world residents.
Is that so? Do you have any numbers or source for that?
Here's my prediction. With flu season on the horizon, and the symptoms of Ebola being a fever and somewhat flu-like, the emergency rooms and doctor's office simply won't be able to respond; especially in areas where Ebola has been present, or near international airports. This is going to either cause false positives, which will incur and tie up resources, to missing actual cases of Ebola.
Even more disturbing is this lackadaisical attitude that is surrounding Ebola and the various diseases now entering the U.S.