Ok. So what if the problem is not training.
Sorry but most of these divers usually complete their courses, do a couple of dives then 2 - 5 years later feel they are ready for that advanced deep dive (or any dive for that matter). Maybe once they could do all the skills, dive with reasonable buoyancy but now they want to dive beyond their training with no refresher course.
You can't really blame their training for this.
Perhaps if more dive centers enforced the refresher course this wouldn't be such a problem. But then I guess most of these people would just lie about when last they dived because after all the refresher is probably some other way LDS's are trying to con them out of money.
We don't need to decertify people, just encourage them to dive more and do some type of skills/diving refresher after periods of inactivity.