I can confirm that Captain Dustin McCabe stated this before one of our wreck dives in particular. He told us don't drop all the way to the sand or you're going to scare the sharks away, and in fact this is what I was thinking when I posted earlier about all the big stuff taking off when they see divers, plus other experiences on dives when I've seen glmpses of big stuff as it takes off when I first begin a dive.
Sure, that happens too but not everywhere, not all the time.