I doubt Andy had any effect on the industry adopting neutrally buoyant instruction. And I'm skeptical about this Herculean effort. Please don't say look it up on scubaboard, as you said here: Failed CESA in OWI think a good reason for this delay can be illustrated in the response it all got on ScubaBoard. There was horrendous pushback against it from several people, including especially Andy Davis (DevonDiver on ScubaBoard and Scuba Tech Philippines). Andy's crusade against neutral buoyancy instruction was simply Herculean. He wrote over and over and over again that using this approach was a violation of PADI standards, and anyone doing it would be expelled. When we quoted PADI leaders, including the CEO and President, to refute him, he said those people only spoke their own opinions, and they were all wrong. (Seriously--he specifically said that any instructor who did what the PADI CEO and President said to do would be expelled.) I believe Andy's fervid opposition represents opposition from others around the world who have fought tooth and nail to impede progress.
Let's try to understand the basic rules of logic.
If you say something exists, and I suggest that it does not exist, it is up to you to prove that it exists. What evidence can I possibly provide to show that something does not exist?