Spinnakers made the reaching legs even more unattractive in the "non-strategical" aspect.

Spinnakers can run pretty deep and so even a mildly spaces reaching leg quickly turns the "downwind" leg into a single spinnaker reach to the bottom-mark without a gybe. This means that, with the exception of the upwind beat, the course has become a parade. And one where the guys winning the first upwind leg has by far the best cards as overtaking other boats in a parade is difficult and will slow you down sufficiently to see the leader walk away.

Something the reaching leg was so long that the spinnaker boats would have to drop the spi on the following broad reach and reach to the bottom mark.

Both these make spinnaker sailing very unattractive c.q. unenjoyable. As most racers were gravitating towards spinnaker cats they actively pushed for a race course without a significant reaching leg. As such the reaching leg became an rather short offset leg (max 200 meters) to maintain some seperation and avoid conflicts at the A-mark. Without that benefit it would have died altogether.

Spinnaker did do that to catamaran race courses; it finished off the triangular race-course in a very short time-frame where it had been struggling to maintain itself under pressure of tactics. It was the sharp and final blow that did it in.

Wouter