You know this debate is about as old as the book. Professor Tolkien acknowledged the problems with the Eagles before pretty much everybody in this thread were born. The truth is Gandalf is dead for barely nine chapters and you really got to wonder if that not the main reason. At the very least book 3 is about separating Frodo from the rest of the Fellowship and cutting his options down to one path. I throw a bigger mindfuck your way that nobody never really debate. In early draft Frodo probably die at Cirith Ungol.
from overview for madhi19 http://ift.tt/1kpFXIy