To add my two cents worth here, a lot of this story seems to stem from the ago-old question of personal judgement.
Diving is risky, but we do it anyway, because we evaluate the risks involved and are willing to take those risks. The decision to go down, or into a cave, into a wreck, slightly deeper, or on 180 bar instead of 220 is something we each evaluate. The further you go in terms of penetration, depth and so on, the greater the risk. Our training, equipment and preparation offset the risk, but there is always more than if we simply didn't go.
The difference between our characters is reflected in where we draw our own lines. This is why some will do tech dives deep into dark cave systems, while others are petrified of the simplest penetrations (or even diving itself). Even at 25m in warm, clear water, I might die. Fortunately, in this day and age, it is very unlikely, so we are still prepared to take that chance. But at the bottom floor of a silty wreck (possibly without a line), that chance is much greater. Fewer of us would go there.
What I draw from this thread is how important this evaluation is. The aim, impossible though it might be, must always to assess EVERYTHING: every possibility of danger, the extent of every possible outcome, every risk, before the decision, during it's course, and afterwards.
As has been said many times herein already, accidents like this are tragic, with the tragedy amplified by the question of how preventable we think it may have been. To the people that knew these divers, and especially those close to them, we show our support and empathy. To the rest of the diving community, we re-establish a timeless and universal lesson.
Edit: It's weird that the post above was entered while I was typing this one.
