If man were a tree, pornography is like taking an axe to his roots. It cuts off his source of strength, weakening his whole being.
"Blessed is the man...
He is like a tree planted by streams of water,
which yields its fruit in season
and whose leaf does not wither.
Whatever he does prospers."
-- Psalm 1:3
...and trees wait, while pornography can only think long enough to say, "Why wait?".