I agree, likely because they were concerned that too many arab men boarding flights at the same airport at the same time. As for security being lighter at the smaller airport, not sure it holds true.
While reading this same document, however, another issue came up...
Now do not get me wrong, I am not "becoming a truther" or anything close, but one thing that puzzled me was the contents of Atta's luggage, held back, and thus not placed aboard AA11.
It contained a copy of the Koran, A tape on how to fly a 757, a folding knife, and a distance measuring ruler.
What strikes me as odd is (A) why put these things aboard your luggage if your are intent on killing yourself and destroying the plane which they will be on, (B) the destruction of the Koran - seems a bit odd to destroy ones own religious text.
Anyway, just one of those things that strikes me as odd...20/20 hindsight wise.
TAM