And what if the storm does track 15 miles further to the west than forecast? That is the point you are missing - the margin of error for the forecast track in a hurricane means worst case has to be prepared for. Two days later is the wrong time to find out that happened and someone did not evacuate.
I am not counseling anyone not to evacuate. My position has always been that people need to make the decision for themselves and not be forced out at gunpoint or state-induced panic.