You can make a case against any form of carry as being dangerous.
Appendix is also on the "is not permitted" list yet I read many who do. In defensive carry classes it's a known risk because of frequent reholstering. And there is a remark about shoulder holsters in this thread - and many ranges do not allow their use in competition.
The point is, what are people doing wrong? The gun is perfectly safe stored in any of these holsters UNTIL THE HUMAN HAND TOUCHES IT. And what are humans trying to do at that point, what is the intent? Extreme speed with increased repetitions as part of practicing.
People trying to be in a hurry and forcing things to happen fast is the common denominator. Design of the holster and it's orientation isn't the major issue, it's the intent to create fast fumbling in practice. Not a fast draw.
IIRC it has been studied that if you want to be proficient in a physical motion you practice it 10,000 times. And many would say a bad repetition doesn't count. Add speed and you increase the bad, error prone repetitions. Speed is the issue. I don't see it as being necessary at all, despite the large number of posters who insist a speed draw is life and death. It obviously increases the risk of a ND and self injury.
It's been preached by others, SMOOTH is better than fast. Fast is actually it's own worst enemy because of the high risk of serious error. SMOOTH reduces that risk while increasing the number of good repetitions to create a more flawless muscle memory set. 10,000 slower, smooth draws are less likely to risk shooting yourself, and smooth reduces errors. Smooth gets the job done. The problem is that human males keep introducing competition over who is better and using the clock to determine it - when the clock is the demonstrated ENEMY of safety which produces injury.
A smooth, confident, practiced and slower delivery of the weapon when you need it reduces error and risk to the holder of that gun and makes for a superior presentation when it's important. This is why range competition is NOT all that for practicing actual confrontations. When you introduce speed you increase risk. Increased risk means we are endangering ourselves MORE on the range in practice and competition than we are by our daily lifestyle of non competitive carry "on the mean streets."
It's said even in today's current events that a cop can carry his service weapon without drawing it to protect his life during his entire career. And yet we read about people getting shot on ranges in competition or class instruction - regardless of what make or position of holster they are using. It's SPEED which is our enemy as it increases risk.
If you are looking to shoot yourself, tho, it's easy - just go faster and practice a lot more for speed than being smooth. You will eventually have your finger on the trigger far too soon on the draw or in reholstering and you will discharge the weapon at your body.