Re: Aikido and Judo/jujitsu
I'm guessing by grappling you mean ground grappling; and by striking/atemi you mean boxing.
Why, exactly Osensei built the system the way he did is up for discussion. However looking at Japanese culture pre-meiji restoration, you can see Japanese martial culture was based around weapons, in particular the sword.
In weapons fighting it is a bad idea to wrestle on the ground, and a bad idea to try to box with your (armed) attacker. Considering that the majority of techniques that make up Aikido were developed pre-meiji restoration, it's a reasonable conclusion that these techniques are weapon focused.
This would explain why Aikido techniques don't apply to ground grappling, and boxing situations, thus the syllabus doesn't contain those techniques.