Except importing lemons are not a known reason for causing accidents and for the most part, margarine consumption doesn't cause divorces. On the other hand, lack of experience does cause airplane accidents. This is a known and provable hypothesis. I don't agree that the 1500 hour rule is THE reason for eliminating accidents. The act has, on the other hand, greatly reduced risk. It has mandated more experienced pilots in cockpits (yes, more hours generally means more experience), reduction in fatigue through FAR 117 and additional mandated training requirements. These have all contributed to a safer, lower-risk operating environment.