Oops, I agree with the general statement, just disagreed with the the Sept 11th significant change.
In the US a lot of the blame (in my eyes) falls to the very public televagelists.and their flaunted opulence. Folks are also leaving churches as pedophile preachers get exposed and churches who hide/relocate alleged pedo preachers pay billion dollar settlements for coverups. Other folks get disenchanted with religious orphanages from those good old days when morality was high that we are finding surrounded by child graves.
There are a ton of reasons folks are leaving the church, or organized religion...and most of the reason lays squarely at the feet of all organized religion.
(I left in elementary school, accused of asking to many questions and not steadfastly bowing to the authority figures...surely no one here is surprised)