The Aikido techniques are weapon techniques.
Saying that you are going to be in an unarmed situation and use Aikido is like saying you are going bowling but not going to use a ball.
The best fly fishermen in the world wouldn't catch a thing if they didn't have a pole and some flies. Techniques are situation dependent, and Aikido's techniques are based on situations involving weapons.
And by that logic I can conclude aikido is meant for persevering history and not self defense. Most of us do not carry the weapons of ancient japan.