you make my point. If the straight-in avoids flying in the pattern, where can he claim final begins? For aircraft in the pattern, it's like a ballet. We're constantly adjusting distance, spacing, and altitude to make the published system work for every one. There is no confusion. Then the straight-in shows up and tries to bully his way onto final, both the straight-in and the base to final aircraft have an unnecessary conflict of ROW interpretation since this situation isn't anticipated by the FAR.
when the straight-in calls a 2-mile or even a 1-mile final and there is an airplane on base, nobody knows exactly what to do. That was the crux of the CA midair problem. The c-152 apparently thought he had time to turn and make the landing, because he couldn't visualize the speed or location of the approaching twin (or any plane travelling at 150 kts).