I think the other side of the coin is that we're moving away from people hiding incompetence through bravado, scapegoating, and what gets neglected when people engage in the game of pretend called "we're all grown ups here". The fact is that people are on a lot of different levels of emotional maturity and function. Even the same individual at difference points of their life and in different contexts. Age only loosely correlates with real maturity, real ownership of responsibility, etc. It's kind of silly when we can plan for all sorts of failsafes and redundancy in architecture and software but neglect to do so with humans, who are always error prone.

Also, it is useful to talk about systemic problems that are much larger than what any individual can fix just by being extra diligent.

I see your point though, that something being nobody's fault can be just as damaging as spending an egregious amount of time trying to assign blame (the traditional way of things). My opinion is that responsibility, and being able to take some flak for when that ownership goes awry, should be conditioned like exercise. Taking none is like never exercising, and it's very unhealthy. Throwing 1000 pounds of weight on someone suddenly because of a pathological need for the group to have a scapegoat doesn't make that person better, though. It just crushes them and it's a net loss for the group. That weight and stress should be shared. We need to cultivate the real maturity to take and give some blame constructively, and recognize all extenuating factors, so that people neither get infantilized and helpless nor simply squashed because of a systemic problem that the group just doesn't want to address.