I didn't know any of these people personally but I had heard of several of them. These were not weekend warriors these were people who climbed during the week and pushed the sport. There are things to learn from every accident but the major trend as I see it is that one mistake is enough. Just one mistake.
When I started climbing I was told of the risk and severity box. There are two perpendicular lines one with the label risk from high to low that something will go wrong and the other the severity of a accident from bearable to deadly. Everyone has to decide where they fit within the box. In high altitude mountaineering the chance that you will have some sort of accident is maybe only a few percent but for the most part if something goes wrong it goes really wrong. Free soloing is an extreme example. Once you're above 30 feet off the ground a fall = death. While you're hiking the Appalachian Trail the chance that you're going to hurt yourself is low and the consequences are a sprained ankle. Everyone has to decide their acceptable level of risk and you should not let anyone make the decision for you. This sport is definitely not for everyone.