Sho, I have two responses to your assertions. One, is that before classical kata training should begin, there are certain "prerequisites." Such as strength, speed, agility, and cardio development, basic striking training, and grappling training. Most pre WWII karate experts understood this and followed this training regimine. In addition to this, many grapplers' game plans go out the window once you start to hit em, hard. A grappling base and using striking as a primary attack on the ground enables the karate fighter to "hang" with grapplers on the ground by simply not playing their game. Now, as far as striking versus grappling in kata it is simple. If a finishing strike/s or a joint lock cannot be successfully applied to an opponent within a short period of time then kata tells you not to stay on the ground, but get up.