You didn't get what I meant... Pilot errors were most frequent (primary) causes of accidents even 40 years ago. And they are now as well, of course. The important thing to notice is that todays total number of accidents (per number of flights or flying hours -- whatever you choose) is significantly (i.e. few times!) less than just the accidents caused by pilot errors those 30-40 years ago. That means than (so) many pilot errors went away. It's either because pilots are so much better today (which is rather hard to belive) or their errors either get corrected or are unable to happen. IOW: those protections do work.
I find your two factor analysis wanting.
The
entire system has improved (in some ways, degraded in others), which includes over fifty years of working at crew skills and crew habits, and the improvement thereof. Likewise, there are a pile of things, inputs that pilots must consider, that inform crew decisions. What 40 to 50 years of continual change has also done is make it more common to fly at the edges of performance (and weather and airspace capacity) margins.
THAT change helps the bottom line, as fewer flights are cancelled or diverted, with associated cost, and along with this benefit the system as a whole gets more comfortable with operating at a higher risk profile. (Take down ATC radar and see what that does to the tightly timed and coreographed spacing around LaGuardia, for example.)
You might want to consider that in your accident and causation analysis.
Also, as another poster raised this point in the other thread ... what behaviors and decisions are rewarded by the company, and by the industry (by pay or strokes or reinforcement) and what are discouraged?
That will influence decision making, and thus your mishap rate.