"The simpler aircraft the more diligent the pilot becomes."
I don't buy it. So a pilot in a twin otter is more "diligent" than a pilot in a 777? Automation and warnings tend to be more prevalent in more complex aircraft. If the gear is down and "welded" that's one less thing to even deal with.
An interesting document that may be worth reading is FAA AC 25.703-1. It helps explain the balance between reasonable levels of warning and (for takeoff config) and overload.