1500 hour rule is simple, it's a survival test, if you are gonna do stupid stuff in a plane, it will most likely be solo. If it kills you you are not a suitable airline pilot candidate. In years past it took a long and tortured road to the airliner, I personally know of at least 10 G/A deaths, due to stupidity. The military filter is tougher, getting through flight training is selective enough, add operational flying and the filter is finely tuned. 3500 hours of 135 freight gives one plenty of opportunities to get dead, the military offers as many if not more. It's about survival, nothing more,,,,