well, in the 1970's, we used to carry an aircrew knife that had a straight blade on it. This was the preferred style. However, it was decided that in order to avoid puncturing the dingy and to aid skinning when in survival mode that it should be relaced with this one (around the mid to late 80's).
Basically, you could do more with the straight blade but they didn't like us playing with knives! I believe the current issue is even more useless.