RR. . .I would say the percentage is more like 95% pilot error. . .we (pilots) are our own worst enemies.  I agree with you idealistically. . .but, this not being a perfect world. . .the reality of the FAA being able to enforce any kind of "don't fly beyond your ability" regulation holds about as much promise as law enforcement keeping some person from driving/operating a land based moving vehicle when said individual is under the influence of alcohol or drugs.  It's sad that pilot Carlson perished. . .to say that when one takes risks when alone is "okay", is not okay.  In this case he crashed into the ocean. . .he could have been over a populated area and the results could have worse.  You're correct though. . .I believe we can do better.