There is ample evidence that this simply is not true. The safety record of the science community demonstrates that with adequate training and a system of oversight diving fatalities can be virtually eliminated.
Well, unless you propose some kind of stringent regulatory system that prevents people from ever getting in the water in scuba gear until they have passed and are diving within such a system, I will stand with the statement I made.
The guy who signed off on my OW card had been diving for three years before he ever got certified. It's not that hard to do. People, like the fellow in Vortex, who are determined to do things that are stupid, are incredibly difficult to foil. You can have the safest imaginable system, but if you can't effectively force people into it, you're still going to have deaths due to stupidity and bad judgment.
We have strong laws against drunk driving, but guess what I see in the ER?